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Discussion Starter · #1 ·
I was wondering what hole sawbits are the best to use for chromoly4130N . I've tried the Bi-metal hole saw bits available at the local hardware stores, and they just don't last at all!!! Are there any that are made to handle the Chromoly better? Thanks for the help. Any advise is appreciated.
Matt
 

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I just bought a cheap 3" bi-metal hole saw to make some coil brackets. I thought I might run into problems drilling through 5"x.25" DOM tube, but it actually worked out fine. The key was to use lots of cutting oil and I kept the press speed super slow. How thick is the 4130 you're using? How big is the hole saw?
 

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I used a carbide holesaw, cutting dom it did not work that well for the price I payed for it .:mad:
 

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I pay more like $8-19 and the carbide might have lasted a couple more cuts .
 

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Discussion Starter · #9 ·
I like that hydraulic notcher. But the project i'm working on is my senior design project for the school mini-baja car, chassis. It's just 1.125" diameter with .058 wall thickness, we've tried cutting oil, cooling, oil, only thing I can think of that would help is running at a slower rpm... b/c we have not been able to make them last at all.
 

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We had no problem using regular hole saw bits on our baja car. We were cutting .082 Chromo with out any probs. Just use oil and slow speed. Should work fine.

Erin
 

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Starrett hole saws rock! After I went thorugh 2 of them trying to figure out the correct pressure and speed to run them at, I can use a single hole saw for an entire cage and more now! I would say that I could probably even make one last en entire buggy if I needed to.

J. J.
 

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Three things that really extend the life of a hole saw:

NO chattering! if it's chattering you're too fast. Most people try to turn the saw too fast. The saw should sling steel out in fairly long strands (if cutting holes in thicker plate). Also use enough pressure to make the teeth actually CUT, not just grind away.

Cutting oil. You HAVE to keep the cutting teeth damp with oil (Liquid wrench or marvel mystery oil works great)

A good ridgid machine. Whether you use a drill press or regular tubing notcher it has to be very ridgid for long saw life. I.E no slop in the bearings, a good vise bolted down to the table, and a drill press with a good HD quill.

Ridgidness should also extend to the hole saw arbor. Most arbors aren't worth the box they came in so I make my own. Assuming you have a chuck that will accept it, take a 3" long, 5/8 fine thread bolt and cut the head off. Thread a matching nut onto it and viola, you have an arbor. Oh- one more thing. There should be some place something can slip if the holesaw binds, like maybe leaving the belt somewhat loose. This may eliminate the occasional carnage.:flipoff2:
 

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starret is number one

patooyee said:
Starrett hole saws rock! After I went thorugh 2 of them trying to figure out the correct pressure and speed to run them at, I can use a single hole saw for an entire cage and more now! I would say that I could probably even make one last en entire buggy if I needed to.

J. J.
What he said!!!! I buy starret at granger. You wont beat the price.

Dan
 
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