knives made from files

[Johnny Diamond]

I have seen several knives for ale that were made from files. I have several questions. I have never made a knife in my life.
1. I have several old files that were my grandfathers. are files tempered? How do you tell which ones are good knife material?
2. I assume the blade is shaped from the file by using a grinder or belt sander or such. Does the metal loose its hardness during this process? Does it need to re-tempered?
3. if it has to be tempered how do you how hot to get it first and when that point is achieved? Can it be quenched in any oil, motor oil?

Thanks.

 

[Black Oak Bladeworks]

This is probably a better question for the maker section. Also the search bar is extreamly helpful, almost everything has been asked at some time.

1 Yes they are tempered, tempered for filing not a knife though. Some might make good knives some probably won't. It is hard to know. Personally, I would buy a piece of 1080 steel. I did some files and other stuff when I started many years ago, it is really hard to know if the file will make a good knife or how to heat treat them correctly. 10.00 for a piece of 1080 or 1095 is well worth it and you will know exactly how to heat treat it. (if you want to make a good user knife that is one of the most important steps.)
2 That depends how hot you get it. If you deiced to use a file and don't want to heat treat it you will have to keep the file cool enough not to discolor it. Many heat treats will start losing the temper at 400 degrees or so depending on the temper and steel.
3 depends what they are made of...

Check out the sticky threads here.

https://bladeforums.com/forums/shop-talk-bladesmith-questions-and-answers.741/

 

[afishhunter]

I'm not sure on knowing when it is hot enough to re-temper. They may go by color.

It has been 50 odd years since metal shop in Jr. High. I don't remember if the 10xx steels can be tempered using water.
If memory serves (no guarantees) we used oil to temper everything.

When I was a fabrication welder in the mid 1970's, I didn't have to temper anything I worked on. (At least I do not remember doing so.)

Yea. All files are hardened. (harder than you would the same steel for a knife blade. If you drop a file on a concrete floor they can shatter. (I've seen it with my own (then) four eyes.) A properly heat treated knife won't shatter.)

Yes, grinding or using a belt sander will destroy the temper, if not kept cool.

I think any but a diamond file would make a good knife, provided you want a carbon steel blade. I am not aware of any stainless steel files. However, that does not mean there are none.
I may be mistaken, but I think files are mostly made from 1070 to 1095 carbon steel.

Question for those who know more than me about files: Are there any files made with 5160 and/or D2 or O1?
I know automotive and light/heavy truck springs have been made using 5160 for over 100 years and counting.

 

[Smiling]

I second that buying a piece of 1080 would be better solution.

Also, if you want to go extra cheap you can probs get 5160 steel for free from some old cars/trucks...

 

[FredyCro]

If your grandad files are in good shape restore them and make new handles. The process of etching and handle making are also important in knife making.
If the files are in bad shape, use them to do a knife. Temper them twice at 200°c for one hour first. You will need at least an angle grinder and couple of clamps. Belt grinder would be nice. When you cut and grind to shape keep everything only to the temperature where you can still handle the steel with bare hands, someone could spray water while you cut, grinding go slowly and cool in between. There are tons of videos on YouTube. It might not be the best or nicest knife but if it makes you dwell deeper in knife making and you like, do it! Good luck and post your progress/questions as you go.