Thread: What caused warp in vintage blades?

Hi:

I have a very old 1/4 -1/2 hollow 6/8 James Barlow Sheffield that has a definite warp. I take it the box every so often and wonder about whether I should restore it.

My question is, is it likely the razor rolled out of production warped or did that occur later? If it occurred post-manufacture, what would lead it to warp? This question has been dogging me for a long time.

Mike Blue might be able to tell you precisely. I know someone told me that after heat treatment the razors are warped, hit with a 'dead blow hammer' and spring back to straight, because steel has a 'memory.' I don't know if there is anything to that but it is what I heard.

I really can't see a blade warping post manufacture. People have snapped blades trying to straighten warped blades. Just wrongly manufactured I suspect.

Bob

Maybe it was made on a friday? On a serious note, the blades are very thin, and the heat treating process can translate to an enormous amount of stress on the metal, mainly during the quenching where the metal is cooled from around 1500 degrees to around 900 degrees in a mater of one or two seconds, this also depends on the type of steel being used. With all that stress, combined with the thinness(yeah i made up that word) of the blade to be treated, any amount of side to side pressure while quenching the blade in oil or water can cause a slight warp. This is usually straightened out immediately following heat treatment, but we're all human, and sometimes it doesn't get quite straight.

The stresses in heat treatment cause the blade to warp, and yes - the forger could 'tap' the blade to take out kinks, but there is only a short period of time to do so - something to do with martensite forming and making the metal less plastic and fully brittle in one minute or so.. Others call it an 'interrupted quench'.

Perhaps the most famous person to actually put this in print was Jean-Jacques Perret in his "L'Art du coutelier' (The cutlers Art) - a handwritten, three volume work made in 1771. In it a faceted hammer head is used on a small anvil - both untempered.

Several period accounts of Sheffield factories make mention of this, too.

Regards,
Neil

Originally Posted by Neil Miller

The stresses in heat treatment cause the blade to warp, and yes - the forger could 'tap' the blade to take out kinks, but there is only a short period of time to do so - something to do with martensite forming and making the metal less plastic and fully brittle in one minute or so.. Others call it an 'interrupted quench'.

Perhaps the most famous person to actually put this in print was Jean-Jacques Perret in his "L'Art du coutelier' (The cutlers Art) - a handwritten, three volume work made in 1771. In it a faceted hammer head is used on a small anvil - both untempered.

Several period accounts of Sheffield factories make mention of this, too.

Regards,
Neil

I love when people agree with me Neil .......

I find it how vintage blades have a tiny lean to the left..the new ones are centered..