Slide 'hardness'?

jmstr · August 25, 2002, 09:15 PM

do any of you have any idea what the rockwell hardness is for the stock Colt 1911a1 slides? I mean pre-70s. I just want to know for comparison purposes.
Thanks

Harry Bonar · January 25, 2005, 11:33 AM

Dear Sir:
You bring up a good question; for years I've thought of buying a Rockwell "C" hardness tester. What I have found in cutting hundreds of slides for sights is that, yes, some are hard, some are soft! Stainless slides are no different, some hard, others soft. I think the average Colt or Springfield Armory slide is somewhere around 30 to 45 on the "C" scale.
On Norinco, I've found that the front of the slide must be softened a bit to cut it even with a carbide cutter (65 degree for Novaks).
To "anneal" a slide at the front will not harm it; bead blast the front (or polish to get a spot not blued) and with a propane torch SLOWLY heat the front of slide to a "blue" color and let cool. You can cut it very nicely then. The rear uses a larger cutter so it usually is O.K.
Chinese carbon steels seem not to have had the temper drawn enough, screwdriver inserts, saws, slides, etc. just seem very "hard." I draw the screwdriver inserts to a blue color and they seem AOK! There is concern in getting the front of that slide too soft - at a "blue" tempering color you're only at "spring steel" temperature so I cannot see the harm in it - do not go beyond that to a grey - some steels will air harden.
Stainless slides, I do not try this! I set the mill on slow speed, use plenty of lube and it does fine.
Be careful, some steels will "air-harden at some low temperatures; a Makarov slide is bad about this; just draw to a straw or brown color if you must on Makarovs'.
Hope this helps.

August 25, 2002, 09:15 PM	#1
jmstr Senior Member Join Date: February 24, 2001 Location: San Joaquin Valley, CA Posts: 1,281	Slide 'hardness'? do any of you have any idea what the rockwell hardness is for the stock Colt 1911a1 slides? I mean pre-70s. I just want to know for comparison purposes. Thanks

January 25, 2005, 11:33 AM	#2
Harry Bonar Senior Member Join Date: December 5, 2004 Location: In the Vincent, Ohio general area. Posts: 1,804	re-hardness Dear Sir: You bring up a good question; for years I've thought of buying a Rockwell "C" hardness tester. What I have found in cutting hundreds of slides for sights is that, yes, some are hard, some are soft! Stainless slides are no different, some hard, others soft. I think the average Colt or Springfield Armory slide is somewhere around 30 to 45 on the "C" scale. On Norinco, I've found that the front of the slide must be softened a bit to cut it even with a carbide cutter (65 degree for Novaks). To "anneal" a slide at the front will not harm it; bead blast the front (or polish to get a spot not blued) and with a propane torch SLOWLY heat the front of slide to a "blue" color and let cool. You can cut it very nicely then. The rear uses a larger cutter so it usually is O.K. Chinese carbon steels seem not to have had the temper drawn enough, screwdriver inserts, saws, slides, etc. just seem very "hard." I draw the screwdriver inserts to a blue color and they seem AOK! There is concern in getting the front of that slide too soft - at a "blue" tempering color you're only at "spring steel" temperature so I cannot see the harm in it - do not go beyond that to a grey - some steels will air harden. Stainless slides, I do not try this! I set the mill on slow speed, use plenty of lube and it does fine. Be careful, some steels will "air-harden at some low temperatures; a Makarov slide is bad about this; just draw to a straw or brown color if you must on Makarovs'. Hope this helps.