[TheForge] Jackhammer bits

[Schade]

Points made by Brunner&Lay are 1045 according
to the B&L engineer I talked to. I got this handout from
him. Maybe 20 years ago. The B&L name is stamped
on the shank.

Bob
___

Instructions for Sharpening and Rehardening Brunner & Lay Moil Points

Brunner & Lay Moil Points are hardened all over and in order to 
maintain this hardness throughout the life of the tool we suggest the 
following procedure:

  To reshape the point, it should be heated to a bright red, preferably 
not to exceed 1700° F. The heat should be very short, not to exceed 1", 
and only sufficient to do the necessary pointing. After forging, the 
tool should be allowed to cool in air. If quenching oil is available it 
would be well to quench the point immediately after repointing and then 
proceed to harden. For hardening, heat the point a very short distance 
back from the cutting edge to a cherry red or about 1450° F. and quench 
in brine about one inch back, leaving a certain amount of heat in the 
steel just above the quenching line. This heat is usually
  sufficient to draw the temper in the point back to a blue color and as 
soon as this takes place, the entire point should be quenched in water.

  The proper tempering heat is 450° F. To observe the temper color the 
point should be polished with an abrasive or by rubbing on a sanded 
board. This should be done immediately on removal from the brine 
quench. When drawing the temper by color, it must be carefully watched 
and the entire point quenched in water immediately the color is 
observed.

  The average blacksmith is inclined to give the steel too much heat, 
both for forging and hardening. It is always advisable to heat the 
steel slowly and harden with as low a heat as possible to obtain the 
required hardness. Also note that the heat must be confined as closely 
as possible to the point to avoid drawing the temper out of the 
remainder of the tool.

  If the tool appears to be soft on the cutting edge, it indicates 
hardening at too low a temperature or too high a drawing temperature. 
Brittleness or chipping is due to hardening at too high a temperature 
or insufficient drawing of the temper.

  Keep the point sharp, because a dull tool is hard on the steel, the 
hammer and the operator. Sharpen them properly and your tools will pay 
dividends on performance.


__


On Jul 15, 2004, at 10:23 AM, PlumDon at aol.com wrote:

> While in the process of scrapping out this week I came across a couple
> hundred pounds of 1" to 1-1/4" jack hammer bits. Could anyone tell me 
> what steel
> they are probably shaped from?  I will offer them up at some upcoming 
> affiliate
> meets but would like to forge and temper one first.
>
> Also found quite a few 2" x 6" track pins from a bulldozer. Any ideas 
> what
> that alloy might be?
>
> Kindest thanks for any advice.
>
> Don Plummer
> Plummer Design Works
> 392 Hallman Mill Road
> Phoenixville, PA 19460
> 610-495-5058
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