8" saw blade heat treat question

C

Capt. Hollis

Joined
May 22, 2017
Messages
11
Would that fall under the L6 category of heat treating . I have access to several used saw blades that Are in the 8" to 12" range . Could I heat treat in an oven in the 450 degree area or is it much higher ? Sorry I'm new to this and learning by the day here.
 
Is this a circular saw blade or a large bandsaw blade from a lumber mill? (These ones might work)

Or is it a large circular saw blade from a home improvement store?
Is it a bi-metal, carbide tipped saw blade, or high speed steel? (These ones will not work.)

Just heating the steel to 450° won't be heat treating the alloy. If anything it would just be tempering it a little which will be softening it up a bit.

Let's talk about actually heat treating an alloy. Let's use 1084, since it can be done in a backyard with minimal kit.

You would likely need to start with thermal cycling it, which means bringing it slightly beyond the Curie point (about 100° hotter than non-magnetic), so a shade brighter or so. Then let it cool to a black heat, them bring it back up to right around non-magnetic, and let it cool again to black. Then back up to a red heat (still magnetic) and let it cool to black for the last time.

Now, you need to bring the 1084 back up over the Curie point (a shade over non-magnetic) and try to keep it held right around there for 30 secs - a minute.

Next- Quench your blade in an oil (canola works fine for 1084) that was heated to 130°, this will keep you from forming a gas jacket that will stop you from cooling your blade quick enough.

Now you have to check with a file for hardness and if the file skates on the steel, you can temper it in an oven @420° or so for 1 hour. After the hour, run it under some cold water and put it back in for a second tempering cycle, afterwards, cool it and then do a 3rd cycle.

This is what would be required with new steel.
The saw blade is a guess at best. You can try cutting it with a hack saw or an anE grinder and filing down past the heated material to get back into the factory heat treated steel.
 
Well Thank You NJ for the great info there. These are carbide blades from the home improvement stores and lumber yards , not large . I have some 1095 here also that I may tinker with , would that be suitable for an oil quench ?
 
Ok, the carbide tipped blades wouldn't work. They have carbide tips attached to a low carbon body. The tips offer the cutting performance needed while the low carbon body offers the shock absorption and toughness required to stop the teeth from shearing off.

1095 is a bit trickier t successfully HT due to it being a hypereutectoid alloy. That means that there is more alloying ingredients in the mix to get put into solution ("dissolved" enough to be able to move to where they want to sit and form the strongest unit).

Due to this, 1095 needs a "soak" at a bit higher of a temp, say possibly 1550-1600 for about 10 minutes to allow everything to get into solution. I am not 100% on the time/temp as I work with 1084, since that is a eutectoid alloy.

There are some others that can be used in a home HT setup. But the three most used are 1084, 5160, 1075, with 1084 being the most popular and likely the most rounded, 1075 being for those that want to attempt a hamon, and 5160 offering a bit more toughness. Though the "most rounded" and "bit more toughness" comments would be Very little, to the point that it may not be worth mentioning.

If you have enough 1095, I would make some blanks and send them out for HT from a professional service, like Peters. There are others, but they just popped into my head.
-------
If you want to try your hand at making a knife from scratch, I would suggest 1084 or 5160. Both should be available from NewJerseySteelBaron. Aldo runs the show there and has quite a range of alloys, and is very helpful to those that have any questions, concerns or problems. Shipping is pretty fast too.
 
NJ you've been very helpful and I will say that 1084 will be on my next purchase list ! I love all the info you have given me and can't Thank You enough ! I am a fishing guide down here in Matagorda Tx and when I get a day or 2 I love to fiddle with the knives . I have successfully made 2 knives out of files and have been hooked ever since
 
No problem, I am glad I could help.
As far as attaching handles, I am sure you have a boat shop locally available, so take a look for West Systems toughened epoxy. It is one of the two that Many knifemakers go with, the other main one is Acraglass.
I prefer West Systems. I had to remove some wood handles and I ended up destroying them, and I had to grind off the epoxy.

Take a look in this section of the forum, it should be right up your alley.
http://www.bladeforums.com/categories/the-great-outdoors.864/

Welcome aboard.
 
Excellent ! I'll sure look them up . I have some other questions on handles but I'd have to pm you . I'm not sure how to do that but I'll try and figure that out NJ
 
As far as actual Private messages, that is known as a "Conversation" on here. But, to be able to have them, you have to be a paid/supporting member, registered does not have access to the option.
 
ok NJ , I'll post another topic on scales and maybe you could help me there . I appreciate all the info you have given me bud
 
You must log in or register to reply here.
Back
Top