Subject: FAQ part 4 of 8

From: [email-masked] (Jim Kirkpatrick)
Date: 3 Oct 94 03:14:11 MDT

This is the FAQ for rec.crafts.metalworking.  It is in several pieces
to keep the overall size of each part below the limits imposed by
some news systems.  This is part 4 of 8.

Generally, units below are United States dollars, degrees Fahrenheit,
and all the other silly backwards units we Americans still use.  Sorry.

The questions being answered in part 1:

0.  Where is this FAQ kept, and where are archives of the newsgroup?
1.  The original rec.crafts.metalworking charter.
2.  The CLOCKS bitnet mailing list, and other related lists.
3.  What are some good books and/or video tapes on metalworking?
4.  Who makes good lathes/mills/etc?
5.  Where do I buy a machine?

The questions being answered in part 2:

6.  What are good magazines to subscribe to?
7.  Where might one take classes or get instruction?
8.  Where can I get raw material for my projects?
9.  Where can I get tools, drill bits, etc.?
10. What are some of the related professional/hobby associations?
11. How do I harden/temper metal?
12  How do I wire up this strange motor?
13. How do I deal with mail-order suppliers?
14. How to sharpen knives, chisels, and other tools?
15. Some safety reminders.

The questions being answered in part 3:

16. How do I drill round holes?
17. What's TIG and MIG?
18. MIG welding technique.
19. Which MIG welder should I buy?
20. Books on welding.
21. Soldering/brazing topics.

The questions being answered in part 4:

22. What are bolt grades?
23. What is XYZ made of?
24. How do I build a furnace or forge?
25. What is Damascus steel?
26. How do I repair/replace this old leather belt?

The questions being answered in part 5:

27. Can I use a drill press as a cheap vertical mill?
28. What is involved in building a steam engine?
29. How do I anodize aluminum?
30. Rust!  How do I deal with rust?

The questions being answered in part 6:

31. Are there any machinery museums?
32. How do I cut metal?
33. What kind of oil should I use on my lathe/mill?
34. What are the various tapers (Morse, JT, R8, etc.)?

The questions being answered in parts 7 and 8:

35. What is Electric Discharge Machining (EDM)?
99. Names and addresses of publishers and suppliers
    (OK, so I got tired of re-numbering it every time a new
    question was added!)

-------------------------------------------------------------------------------

22.  What are bolt grades?

     We frequently see questions regarding bolt grades, so here's a partial
     list.  Please note that just because a bolt is grade 2 does not mean
     it will break easily.  Grading only refers to the minimum strength,
     not the maximum.  Thus, if a machine uses a soft bolt as a safety
     shear pin, and you happen to replace it with a grade 2 bolt that was
     actually manufactured to grade 8 specs (but was marked down because
     too many of the bolts in the lot failed, so the whole lot was marked down)
     you could create some serious problems.  Replace safety-related items
     with proper stuff!  Also beware of improperly-marked forgeries.  If
     your application is critical, test some samples or get certified
     hardware (not that readers of rec.crafts.metalworking are likely to
     be building interstate bridges or spacecraft, but it's worth saying).

     A note on "strength" which is actually a complex subject.  First,
     note that there is a maximum "dry" tightening torque, and that
     part of this torque goes to overcoming friction.  Thus, a lubricated
     bolt should be tightened to a lesser torque, as much as 1/2 the
     dry torque.  Note too that bolts are rated as to their minimum
     tensile strength (presumably before breaking) and also their
     "proof" load, which is I believe the maximum load they can be
     subjected to as proof of their being grade "n", but this load
     is higher than the maximum suggested operating load.  Thus, like
     automobile mileage figures, use these numbers for comparison only.
     I suggest reading the below-listed references before building any
     life-critical contraption.  And remember that tensile strength
     is not the same as shearing strength.  And note that there have been
     many scandals over the years involving manufacturers or distributors
     who certify hardware as high grade, incorrectly.

     John M. Peterson kindly typed this in on July 20, 1993, and I
     have added a few strength figures (jk):

     Taken from  Machinery's Handbook 23 , page 1286.
     Torque: see Pocket Ref, by Thomas Glover, page 250.
     Strength: Standard Handbook for Mechanical Engineers, 7th ed.,
        page 8-35.  This also has a table of safe loads, as well
        as tensile and shearing strengths.

-----------------------------------------------------------------------------
ASTM and SAE Grade Markings for Steel Bolts and Screws
-----------------------------------------------------------------------------

Grade Marking           Spec.                Material
-----------------------------------------------------------------------------
                        SAE - Grade 1        Low or Medium Carbon Steel
       No               ASTM - A 307         Low Carbon Steel
      Mark              SAE - Grade 2        Low or Medium Carbon Steel

-----------------------------------------------------------------------------

     --  --             SAE - Grade 3        Medium Carbon Steel

-----------------------------------------------------------------------------
        |               SAE - Grade 5        Medium Carbon Steel
                                               Quenched and Tempered
                        ASTM - A 409
     /     \
                        Min Tensile Strength: 105,000 to 120,000 psi
                        Proof load: 74,000 to 85,000 psi
-----------------------------------------------------------------------------
        |               SAE - Grade 5.2      Low Carbon Martensite Steel
     \     /                                   Quenched and Tempered

-----------------------------------------------------------------------------
        |
      -- --             SAE - Grade 6        Medium Carbon Steel
        |                                      Tempered

-----------------------------------------------------------------------------
        |               ASTM - A 325         Medium Carbon Steel
                          Type 1               Quenched and Tempered
      A 325                                    Radial dashes optional
     /     \

-----------------------------------------------------------------------------
        |               ASTM - A 325         Low Carbon Martensite Steel
     \     /              Type 2               Quenched and Tempered
      A 325

-----------------------------------------------------------------------------
                        ASTM - A 325        Atmospheric Corrosion (Weathering)
                          Type 3               Steel, Quenched and Tempered
      A 325
      -----

-----------------------------------------------------------------------------
                        ASTM - A 354         Alloy Steel,
                          Grade BC             Quenched and Tempered
       BC

-----------------------------------------------------------------------------
        |               SAE - Grade 7        Medium Carbon Alloy Steel
                                               Quenched and Tempered,
    --     --                                  Roll Threaded After Heat
     /     \                                   Treatment
                        Min Tensile Strength: 133,000 psi
                        Proof load: 105,000 psi
-----------------------------------------------------------------------------
        |               SAE - Grade 8        Medium Carbon Alloy Steel
     \     /                                   Quenched and Tempered
                        ASTM - A 354         Alloy Steel,
     /     \              Grade BD             Quenched and Tempered
        |               Min Tensile Strength: 150,000 psi
                        Proof load: 120,000 psi
-----------------------------------------------------------------------------
       \/               SAE - Grade 8.2      Low Carbon Martensite Steel
     \    /                                    Quenched and Tempered
    \      /

-----------------------------------------------------------------------------
                        ASTM - A 490         Alloy Steel,
                          Type 1               Quenched and Tempered
      A 490

-----------------------------------------------------------------------------
                        ASTM - A 490        Atmospheric Corrosion (Weathering)
                          Type 3               Steel, Quenched and Tempered
      A 490
      -----

23.  What is XYZ made of?

     Metals

     1. What is Brass made of?
        Brass is a combination of copper and zinc, in approximately the
        ratio of 2/3 to 1/3, respectively.  Sometimes lead (about 3%) is
        added to improve machinability.

     2. What is Bronze made of?
        Bronze is usually made of copper and tin.  However bronze
        describes any bronze colored alloy even if it doesn't have any
        tin.  Various bronze alloys include silicon, manganese or
        phosphorus.  Mostly bronze is used for bearings.

     3. Steels
        Steel is a refined iron where the impurities carbon, silicon,
        sulphur and phosphorus are removed and then the iron is
        combined with carbon and/or chromium and/or nickel.  Various
        other metals may be added to create a nearly infinite variety of
        steel and steel alloys.  A few common steels are discussed
        below.

        a. What is CRS?  Cold Rolled Steel.

        b. What is HRS?  Hot Rolled Steel.

        c. What is HSS?  High Speed Steel.

        d. What is stainless steel?
           Stainless steel is low in carbon but has about 20%
           chromium.  Stainless has a beautiful finish but it is
           very hard to machine.

        Both CRS and HRS are mild steels.  Mild steels have a low carbon
        (<.3%) content and therefore can't be hardened.  CRS is formed
        (into bars, rods or angles ...) "cold" and therefore has
        internal stresses inside.  Because of these stresses, an
        intricate part, like a one piece crankshaft, or a heat treated
        part may distort.  CRS has a smooth surface, which requires no
        additional finishing.  The steel stock found in the hardware
        store or home improvement center is usually CRS.  HRS is formed
        hot so it does not have any internal stresses but it has a
        rough black scale surface.  HRS is a little cheaper, but CRS is
        easier to find.  HRS is used for welding, so a welding shop with
        steel stock would be a good source for HRS.  HSS is a carbon steel
        (0.3%<carbon<1.7%) that also contains tungsten.  HSS is used to
        make tool cutters (drills, taps, dies...).  HSS cannot be easily
        hardened or annealed in the home shop.  Drill rod and tool steel
        are also carbon steels that can be hardened and annealed in the
        home shop to machine custom tools.  But they cannot take the
        heat of, nor do they wear as well as HSS.

24.  How do I build a furnace or forge?

     Geoffrey Keyes posted this on August 26 1993, and it looked good enough
     to include in the FAQ.  JK

     Ok boys and girls, I'm going to attempt to put together what I know about
     propane forges/furnaces.  This may be somewhat rough since I am doing
     this extempore.  I'll be happy to answer any specific questions people
     may have.

     A disclaimer up front.  I am not an expert on these beasts and I am not
     responsible for any injuries, deaths, fires, unexplained explosions, or
     irate neighbors.  The following is what I have tried or seen tried.

     A little history.  I first saw one of these in operation at a North West
     Blacksmith Association (NWBA) novice class about six years ago.  Since
     then I have built three versions, Mk III is operating just fine today.
     I hope to be operating, part time at least, officially as Ravens Forge by
     the first of the year.

     Gas furnaces are commonly called forges.  In fact, a forge is open topped
     and a furnace is closed.  In my opinion an open topped version would lose
     too much heat to be valuable.  The two basic types I've seen have been
     1) The brick pile,
     2) The pipe or box.

     Basically, the furnace is a closed space, open at one or both ends, lined
     with insulation, with an inlet for air and gas to enter.

     THE BRICK PILE
     Just what the name suggests, is a pile bricks with a pipe stuffed in one
     side.  The bricks are stacked to provide an open space and the air inlet
     is inserted into the space.  A fan is attached to the end of the pipe
     and the gas line enters between the fan and the box.  The opening is
     covered by a stack of bricks which can be moved around to provide an
     opening big enough for whatever stock is being used.  Since I haven't
     mentioned it until now, these bricks are fire or refractory brick.
     Normal red brick will explode under the thermal stress and even fire
     brick will break down over time.

     The first brick pile I saw is still in use.  The problems with them are
     they leak flame and unburned gas though all of the joints and they
     generally lose too much heat for welding.

     THE PIPE
     This is what I am using today.  Same basic form, a closed box, insulated,
     with a pipe for the air and gas to enter.

     My furnace is a piece of 1/4 steel pipe, 16 in long, with a 1/4 plate
     welded on the back.  About half way down one side a piece of 1 1/2 in
     pipe is welded to the body.  There are two pieces of angle iron welded
     to the bottom of the case to keep it from rolling over and a shelf welded
     to the opposite side of the case from the inlet pipe.  I use the shelf to
     preheat steel and to keep my tea cup hot.

     Attached to the end of the pipe is a fan, in this case an old hair dryer.
     About midway between the fan and the case there is a hole drilled for the
     gas inlet.  I use two inches of insulation (on which more later) in the
     case and a pile of fire brick to close up the open end, with just enough
     space for my stock to enter.  The gas source is a 5lb propane bottle.
     The whole thing sits on the end of 55 gal drum.

     The air/gas inlet can be as simple as a piece of pipe or a complicated
     as you like, basically you're going to have to experiment with the size
     of the outlet end.  I put a twisted piece of steel in the end of mine
     to impart some swirl to the gas as it enters the furnace.  This works,
     but not as well as I would like.  Don't push the end of the tube to far
     into the furnace, since it will just burn off.  This is a sort of self
     correcting problem since if it is too far into the fire it will just
     disappear over time.

     I've got a valve on mine, between the fan and the gas inlet.  However,
     my fan is too wimpy for me to use the valve much.  The fan is blowing
     its heart out just keeping up.  My next modification will be a burlier
     fan.

     INSULATION
     The insulation used by most of the smiths I know is called KAOWOOL, which
     is a Johns-Manville product.  There is also INSWOOL made by A.P. Green.
     Both of these are spun ceramic blankets.  WARNING The ceramic fibers are
     fairly friable when the blanket is new and unheated.  I suspect that
     breathing them is a bad idea, so use a filter mask when building your
     furnace and during the first firing.  After that the surface gets hard
     and crusty and the problem seems to go away.

     Some smiths I read about have used castable refractory cements to build
     furnace bodies, but I don't have any direct experience with them.  Fire
     brick, KAOWOOL, and the like can be found under "Refractories" in the
     yellow pages or try ceramic supply houses.  I bought my first KAOWOOL
     from a ceramic supply.

     LIGHTING UP
     This is an exciting process.  First insert a burning piece of paper into
     the fire box, turn on the fan, then turn on the gas.  There should be a
     whump and then a burst of flame.  Now adjust the gas so that fire is not
     streaming out of every crack.  Give it enough time for the box to heat
     up (2-5 min) and off you go.

     SAFETY
     Propane is a flammable, heavier than air gas.  It will accumulate on the
     floor until it gets a spark.  Then it burns very fast.  If enclosed at
     all it will explode.  Check all of your valves and connections frequently.

     A regulator AND a blowback valve are a good idea.

     I got most of this info word of mouth and by trying it out myself.
     However, there are some publications that may be helpful.

     The summer 1991 Vol 5 Num 3 of Knives Illustrated has a pair of good
     articles on gas forges.

     ABANA
     P.O. Box 1181
     Nashville Indiana 47448

     This is the largest blacksmiths association in the US and is a source
     for all kinds of good stuff.  In particular they sell plans for a furnace.

     "A recuperative gas fired forge furnace"
     Sandia National Labs.

     I don't know what they charge for these plans anymore.

     W.L. Goddard
     473 Durham Ave.
     Eugene OR 97404

     Wayne writes a column for BLADE magazine and is an ABS Master Smith.
     He also used to sell a pamphlet of basic bladesmthing info including
     a section on gas furnaces.  I don't know if these are still available.

     As I said above, I am not an expert and am not responsible for any
     problems, injuries, or unexplained fires that might result from any of
     the above info.  On the other hand, I have used a furnace described above
     to forge and heat treat approximately a dozen knives with good results
     and no injuries or other accidents.  If there are questions or if things
     are not clear (almost a certainty) please feel free to contact me at

                [email-masked]

     Good forging

     Geoff Keyes
     Ravens Forge

     ----------------------------------------------

     Another recommended book is "The Complete Bladesmith" subtitled
     "Forging Your Way to Perfection", by Jim Hrisoulas.  ISBN
     0-87364-430-1, published by Paladin Press.

25.  What is Damascus steel?

     We often see the question "what is Damascus steel" and the next
     question, "how do I make it" or "where do I get it".  In an attempt
     to answer this question, I've put together several responses that
     have shown up in the past.

     ---------------------------
     From: [email-masked] (RICHARD ALLAN JOHNSON)
     "Damascus" steel is usually created nowadays when 2 materials with
     differing carbon content or differing properties such as high and low
     carbon or high carbon and nickel are forge welded together to form
     one solid billet.  My experience is that in general, Damascus does
     not stay shaving-sharp as long as straight carbon steel but when it
     dulls it leaves a microscopic saw edge that will cut flesh like
     nothing else.
     ---------------------------
     From: [email-masked] (SCOTT F. MASTROIANNI)
     Simply speaking, Damascus steel is an antiquated term popularly used
     to describe various pattern welded steels.  The term was originally
     used to describe steel from Damascus which had intricate and subtle
     patterns in it due to the way the steel was made and wrought -- the
     pattern was a by-product rather than a set goal.  These steels
     contain alternate layers of differing alloy steels that have been
     forge welded together into a single laminated billet.  Frequently
     these billets are then twisted or physically manipulated in some
     other manner and/or rewelded to other similar billets.  After this
     laminate steel has been formed into the final shape for which it
     had been destined, i.e. a knife, object d'art, etc. it is usually
     etched with some strong acid solution.  The etching process will
     affect the different alloys in different ways; some will etch deeper,
     producing a noticeable topography, and some will turn darker.  The
     effect is to produce a pattern in the steel of great contrast and
     beauty.

     A Damascus or pattern welded steel blade does not have to be any
     weaker than single alloy, and frequently it is as good if not better
     in all properties: edge holding, toughness, cutting ability,
     sharpenability.  It is usual practice to use a high carbon and a low
     carbon alloy as the constituents of a Damascus blade.  This unites
     the best of both worlds:  The high carbon steel grants the blade its
     cutting ability while the low carbon alloy adds to the toughness and
     shock resistance.  It is not necessary to use low carbon alloys at
     all.  Two high carbon steels with greatly differing trace element
     profiles can be welded to show patterns.  I have even read of 440C
     stainless being forge welded to tool steel -- this can't be an easy
     process though.  In addition, if the pattern in the blade is complex,
     and many of the laminations cross perpendicular to the edge of the
     blade, micro-serrations are formed which add to the cutting ability
     of a well-made Damascus blade.

     Wayne Goddard, a Master Bladesmith of the ABA and a colleague of
     Jim Hrisoulas (whose book I recommend for a much better treatise on
     this subject than I have given here), has a continuing program of
     testing the properties and performance of forged blades.  He has
     tested hundreds of blades, and found that well made pattern welded
     blades cut and hold their edges just as well as single alloy blades.
     The Damascus blades are usually much tougher than all but the
     strongest (52100 or 5160) single alloy blades.

     In addition to _The Complete Bladesmith_, I heartily recommend
     "The Blade" magazine to anyone interested in the latest developments
     in Pattern welded steel and knifemaking in general.
     ---------------------------------
     Robert Allen, [email-masked], wrote:

     I've had the opportunity to discuss Damascus manufacturing with
     Jerry Fisk and John Smith, two makers who do excellent Damascus.
     Let's see if I can remember the basics:

     "Damascus" as used by most makers today means a layered material made
     from a mixture of high and low carbon steels.  Makers differ the mix
     according to their pet mixes.  A billet of alternating layers is forge
     welded, then folded and re-folded to the desired number of layers.  I've
     been told that more than 200-300 layers is counter-productive, as at
     that point you start to get too much carbon migration between the layers
     and you end up with a homogeneous medium carbon steel.  The point of
     Damascus, I've been told, is that the high carbon component gives up
     a bit of carbon to the low carbon component.  When the blade is hardened,
     the high carbon component gets fairly tough, which gives you good edge
     holding, and the low carbon component gets a little harder.  The point
     of all this is that damascus is supposed to have a "micro-serrated"
     edge, which lasts a long time.  The theory as I understand it is that
     the low carbon component wears faster than the high carbon component,
     giving you an "aggressive" edge that can't be beat.  The two Damascus
     blades I have seem to bear this out, beyond what merely varying the
     the grit on a sharpening stone would do.

     After forging a Damascus blade, it is etched in one of several acid
     mixtures, which causes the pattern caused by the layering to emerge.
     Typically damascus is then blued to bring out the contrast between
     the layers.  Damascus is often modified by forming to create specific
     patterns in the steel.  Some makers have produced small American flags
     in the pattern.  Note that such patterns are produced strictly for
     the sake of art, not for performance.  Popular performance oriented
     patterns are ladder pattern (has ladder "rungs" the length of the blade),
     San Mai (various makers wrap a carbon steel layer between two damascus
     layers), random pattern, etc.  Some makers claim the different patterns
     offer different structural or cutting advantages.  The patterns are
     made by machining the billet or blade with the pattern, then re-heating
     and the material and hammering it flat, etc.  There is also cable Damascus
     which is forge welded cable.  Most makers I've spoken with told me their
     cable Damascus looked good, but wasn't as strong as the other Damascus.
     Cable Damascus has a unique reptile-scale type pattern.

     A good Damascus should OUT-perform straight carbon steel in most areas,
     but particularly in edge holding.  Some makers say their Damascus is
     not as springlike, and so the blades will not spring back as close to
     true as a carbon steel blade will, under a vise-bending test.  I've found
     that most famous makers are honest about their Damascus.  Tim (?) Winkler
     told me he makes Damascus strictly because it looks nice.  Wayne
     Valakovich (sp?) told me that his normal Damascus isn't as good as his
     carbon steel, but that his high-density Damascus is better.  Fisk and
     Smith both say their Damascus is better than their carbon steel in most
     regards, although it still is not as springlike as their high carbon
     blades.

     I've cut down small trees with a Fisk Damascus blade, with no apparent
     wear on the edge.  I have a Smith bowie which cuts through blue jeans
     with zero apparent effort.

     -------------------
     [email-masked] suggests that knife blanks may be available from
     K & G Finishing Supplies, (602) 537-8877.  Also everything else you
     might need to finish a knife.

     Books that discuss Damascus steel, either historically or how-to:

      Custom Knifemaking
      10 Projects from a Master Craftsman
      Tim McCreight
      Stackpole Books 1985  ISBN 0-8117-2175-2
      7 1/4" x 9 1/4" 222 pg. paperbound  ($14.95, $20.50 in Ca. when I got it)

      A History of Metallography:
      The development of ideas on the structure of metals before 1890
      by Cyril Stanley Smith
      1960 -- The University of Chicago
      Library of Congress Catalog Number: 60-7243

      "DAMASCUS-USA" distributes a catalog.  It says on the cover
      "World leader in hand made forged-to-shape Damascus Cutlery Steel.
      More of our knives are in use world-wide than anyone else's."
      It looks like they mostly sell ready-made Damascus knives but there
      is a page where you can order Damascus Billets (Bar stock) in any
      size or pattern.  This apparently is a one-man operation, by
      Dr. Robert Charlton 919 482 4992.

      The book "The Complete Bladesmith" by Jim Hrisoulas has also
      been recommended.

26.  How do I repair/replace this old leather belt?

     A big problem with some lathes is that the drive belt, or
     one/some of the belts, are assembled with the lathe and are
     not meant to be replaced without disassembling the headstock.
     This is a task that is difficult at best.  Older South Bend
     and others use a flat leather belt, glued or stitched.  Newer
     lathes sometimes use a V-belt in the headstock to transfer
     power from one set of pulleys to a set of pulleys on the
     spindle.

     For V-belts, there is at least one linked replacement.
     Gates Rubber Company makes "Nu-T-Link" belting that can
     be cut to length, threaded into position, and joined with
     special T-pins.  The pins might get in the way, depending
     on the application, so be careful to check out clearances
     before you buy.  (ref: HSM Jan/Feb 1992 pg 6-7).  You might
     look in the yellow pages in your area for bearing/belting
     or other mechanical suppliers.

     Flat leather belts sometimes just start slipping well before
     they break.  One suggested fix was to apply "friction tape"
     to the pulleys, especially if they are polished.  It needs
     occasional replacement, but is cheap and easy.  Another fix
     is to apply some sort of belt dressing; one person suggested
     contacting New England Belting in Springfield MA.  They may
     also be able to supply a replacement.  Also try Hudson Belting
     in Worcester Massachussets at (508) 756-0090.  A non-leather
     replacement is called Texalon, made by J.E. Roads & Sons,
     2100 West 11th street, Wilmington DE 19899 (phone (302) 655-6513).
     It is sold through Hermance Machine Company, 178 Campbell Street,
     Williamsport PA 17701, phone (717) 326-9157, and possibly others.
     (ref: HSM March/April 1993, pg 8-9).  Texalon is cut to length,
     the ends prepared, and then glued.

     At least for Logan lathes, there is the manufacturer:
          Logan Actuator Co.
          4956 N. Elston Ave
          Chicago, IL 60630
          (312) 736-7500, (312) 736-6854 (FAX)

     I have also heard of stitching a brass cabinet hinge onto a
     leather belt, then assembling in place (as long as the hinge
     pin can be secured from dropping out!).

     Also, per a post 5/17/94, try Page Belting in Concord, New Hampshire.