Where can I buy decent HSS blanks from Canada?

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martik777

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I've need to reduce a bunch of 1/2" set screws down to .410" for 1/2" or so but my HSS wears fairly quickly. It's a old momax piece I ground for with a 45degree chamfer. I've tried some Chinese HSS but it dulls on the 1st piece. Also tried some DCMT inserts but they are not sharp enough to allow easy threading on the screw after machining. Tool bit is about 1/4" square and ground like a threading tool with a 45degree angle and front rake of 3-5degrees, no top rake.

I cannot find any source in Canada for decent HSS, only Chinese stuff.
 
martik777 said:
I've need to reduce a bunch of 1/2" set screws down to .410" for 1/2" or so but my HSS wears fairly quickly. It's a old momax piece I ground for with a 45degree chamfer. I've tried some Chinese HSS but it dulls on the 1st piece. Also tried some DCMT inserts but they are not sharp enough to allow easy threading on the screw after machining. Tool bit is about 1/4" square and ground like a threading tool with a 45degree angle and front rake of 3-5degrees, no top rake.

I cannot find any source in Canada for decent HSS, only Chinese stuff.
Click to expand...
Did you look at KBC? For example:

PRECISION MARSHALL,3/8SQ.X3IN DYNAVAN T15 USA TOOL BIT,1-408-00619,KBC Tools & Machinery

PRECISION MARSHALL,3/8SQ.X3IN DYNAVAN T15 USA TOOL BIT,1-408-00619,KBC Tools & Machinery
www.kbctools.ca www.kbctools.ca

I'm surprised that a piece of Momax isn't up to the job, though. Are the set screws hardened? (How many do you have to do?) What speed where you running at? The geometry you described doesn't sound very appropriate for turning off the existing threads. If I understand correctly, you want to turn off the existing threads and then single-point new threads at the reduced diameter?

Craig
 
You don't only use Iconnel set screws? They are the bomb man. :grin:

Does it have to be a single tool for turning and threading? Those are such different operations that I would expect the tools to not work well for both. For HSS, I would use a simple square tool for turning, and a ground 60 degree for threading. If the material is hard enough that HSS isn't up to it, the existing DCMT tool for turning, and thread with a laydown insert.

I have some of those Dynavan T15 blanks. They are tough. You do still need to slow down to HSS speeds though. If you're trying to keep speeds up, you probably need carbide.
 
WCraig said:
Did you look at KBC? For example:

PRECISION MARSHALL,3/8SQ.X3IN DYNAVAN T15 USA TOOL BIT,1-408-00619,KBC Tools & Machinery

PRECISION MARSHALL,3/8SQ.X3IN DYNAVAN T15 USA TOOL BIT,1-408-00619,KBC Tools & Machinery
www.kbctools.ca www.kbctools.ca

I'm surprised that a piece of Momax isn't up to the job, though. Are the set screws hardened? (How many do you have to do?) What speed where you running at? The geometry you described doesn't sound very appropriate for turning off the existing threads. If I understand correctly, you want to turn off the existing threads and then single-point new threads at the reduced diameter?

Craig
Click to expand...
No, I'm not threading, just turning off the existing threads for length of 1/4-1/2" and need a good remaining 1/2-13 thread. If I use the DCMT or brazed carbide it galls the thread so I cannot easily thread on a nut after cutting the chamfer.

Set screw is 2" long. Running 4-500rpm. They are fairly hard but I can file them. Chips are little dark bluish curls about 1/8th inch long. Need to do 100's.

I prefer to do the cut and 45 degree chamfer with the one tool.
Right now I do one pass to get 90% of the material off, then 2 spring passes to dimension

Thanks, I'll checkout that HSS at KBC. I'm also looking at these: https://www.aliexpress.com/item/4001294281524.html?spm=a2g0o.9042311.0.0.2bc44c4dMNwtv9


See photosetscrew.jpg
 
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It's hard to see the profile on your cutter but assuming it is close enough have you tried to rotate the tool post a bit so it's more pointy where it meets the part? I've done some of this work before and it seems like the hard stuff sometimes needs a point to work through the hardened exterior. So then what happens is you need to tweak your feeds to get the finish you are after. I am always learning but looking at your picture, even if the parts are hard as hell, you should be able to do 10-15 of them (at least) before you need to touch up your HSS cutter with a stone. Do you have some good stones you can quickly sharpen your cutter with? They are not all created equal. Are you using any cutting fluid? That should get you a few more between stone work too.

EDIT: Maybe a couple shots of your cutter from different angles would help.
 
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