Thread: A Spyderco straight razor is in the works....

Nice graph. Some time ago I made up some experimental blades that found their way to midwestern honemeisters. The intent was to discover the sweet spot for honing and shaveability and edge durability. That turned out to be Rc 59.5 I think the graph's carbon content estimate is a little low on the low end. 0.91-1.00%C is better. It depends on the source referenced.

As tested in my shop using my HT methods, I can ritually produce bainite in O-1 at Rc 59.5. Time at temperature is the key. The graph agrees with me. This meets the sweet spot requirement and adds considerable toughness to the equation.

Inevitably this is a criteria frought with subjectivity. Any one batch of steel from a manufacturer can vary from expectations. There are a lot of it dependses...

Originally Posted by Mike Blue

Inevitably this is a criteria frought with subjectivity. Any one batch of steel from a manufacturer can vary from expectations. There are a lot of it dependses...

While that is true, you have the advantage that 1 batch of steel is so large that you can dial in the heat treatment to that specific batch. You may have to tweak the parameters with the next batch, but by then you're already many thousands of blades further.

A steel mill typically, at least the products my company uses, does a run on the order of 20,000 pounds of steel. The problem you'll face is a distributor may order from multiple mills, based on who is cheapest.

To help with this, request "material certifications" and should be free of charge. A mill will produce and supply them to distributors and it should contain material composition, stress/strain data, etc. This will at the very least give you a more accurate carbon content, not a range like in a ISO/ASTM standard.

Originally Posted by dinnermint

A steel mill typically, at least the products my company uses, does a run on the order of 20,000 pounds of steel. The problem you'll face is a distributor may order from multiple mills, based on who is cheapest.

To help with this, request "material certifications" and should be free of charge. A mill will produce and supply them to distributors and it should contain material composition, stress/strain data, etc. This will at the very least give you a more accurate carbon content, not a range like in a ISO/ASTM standard.

Yes, thanks dinnermint! One conversation I had today was with a steel supplier.

The prototype is on display at the Spyderco booth at SHOT Show in Las Vegas this whole week. It's being handled and discussed with positive feedback. The idea of a simple steel heat treated to bainite is the basis for the first run.

Feedback from here has been helpful. You all are having an impact. There is enough in the list of requested features for several design changes for future projects. I'll try to get a picture up tomorrow.

If it is currently on display at the SHOT show, would it be possible to have a photo of it posted on here?

Bob

Mike,
The prototype razor you mention in your OP sounds well thought out andI would be quite interested in one as long as Spyderco can keep costs down. I too have 2 of their chef knives and they are fantastic.

As to the hole, it's a Spyderco. We all have Q-Tips in our bathrooms...no problem.

Bainite vs martensite? I bet very few of us have have bainite straights. This would be one of those"leave it to the professionals " IMO. Less chippy would be good, Hart went through a growth stage.

Is the timing right? I am talking about the market. In my minds eye, interest in straights may be stagnant. Would it worth doing a production run? With Spyderco's reputation for making quality products, I would say yes.

Did you mention a barber notch? Thats a must!

Attachment 315336

The K11P is spectacular, vg-10 steel, we have two of them.

Also have two Featherweight Bill Moran hunting knife collaborations in the same steel. You chose a good partner to work with.

Originally Posted by ScottGoodman

Mike,
Bainite vs martensite? I bet very few of us have have bainite straights. This would be one of those"leave it to the professionals " IMO. Less chippy would be good, Hart went through a growth stage.

Take this unverified informatio fwiw, but I have been told that the water hardened wootz razor I recently sold was likely bainite. Timothy Mitchell says that a water hardened wootz razor has a bainite edge instead of martensite. Oil quench or other steel will result in martensite.
It 'did' etch differently. Very noticeably so.
I discussed it with Howard and he said it 'could' be true but we'd need proper analysis to know with certainty.

Originally Posted by Bruno

Take this unverified informatio fwiw, but I have been told that the water hardened wootz razor I recently sold was likely bainite. Timothy Mitchell says that a water hardened wootz razor has a bainite edge instead of martensite. Oil quench or other steel will result in martensite.
It 'did' etch differently. Very noticeably so.
I discussed it with Howard and he said it 'could' be true but we'd need proper analysis to know with certainty.

O-1 bainite structures take about an hour to develop to 100%. Water hardening steels are not known for developing bainite. "It depends" is always an operating factor. The other limitation is that the Heat Treater's Guide does not have any pages devoted to wootz. Isothermal transformation diagrams are a great help for deciding if it can be done much less how.

Since we are both here, I'll ask him.

Originally Posted by BobH

If it is currently on display at the SHOT show, would it be possible to have a photo of it posted on here?

Bob

Bob I will do my best to get a photo up soon.