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Supporting => Engine Ancillaries => Topic started by: Mosey on April 05, 2015, 01:31:58 PM

Title: Heat Treating Tiny Parts
Post by: Mosey on April 05, 2015, 01:31:58 PM
I am making some valve retaining E-Clips for my Silver Bullet because the ones I need are no longer carried by MSC or others. They are 0.195" in overall diameter, for a 0.109" groove, and 0.025" thick. Tiny.
I made them out of drill rod and now need to make then a little springy.
How should they be heat treated? Dull red and then quench? Quench in oil or water?
Mosey
Title: Re: Heat Treating Tiny Parts
Post by: Jasonb on April 05, 2015, 01:41:30 PM
What you quench them in will depend if you used oil or water hardening rod though on something so small probably not that critical.

You will also need to temper them as the first quench from red will leave them very brittle and likely to snap as soon as you try to open them up probably need to be looking for dark purple to blue in teh colour 270-300deg C
Title: Re: Heat Treating Tiny Parts
Post by: jerry kieffer on April 05, 2015, 03:58:09 PM
I am making some valve retaining E-Clips for my Silver Bullet because the ones I need are no longer carried by MSC or others. They are 0.195" in overall diameter, for a 0.109" groove, and 0.025" thick. Tiny.
I made them out of drill rod and now need to make then a little springy.
How should they be heat treated? Dull red and then quench? Quench in oil or water?
Mosey

Mosey
      Actually , hardening small parts can be a challenge.    The Issue is that they very rapidly cool and often drop below quench temp. before hitting the quenching fluid from the flame.

Two solutions if its an issue.

First, start with  A-2 (Air Hard) and follow Manufacturer instructions.

Second, you can machine a stainless container for the part or parts, and then heat both container and part in the container.   The container should be large enough to retain high hardening temps per any machinist handbook.

However in this case, hardening and spring tension are not required with a slight design change.   You can machine a slot in round stock for a clip and then machine a pocket in the top of the valve cap to hold it in place.

For future reference where parts with spring action are required.

I would suggest that the parts be machined from  spring stock available from a gunsmith supply house such as Brownells and follow hardening/tempering instructions.

Jerry Kieffer
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