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Discussion Starter · #1 ·
i have tried opening up the hole on the pitman arm where the ball joint fits, i want to pput a bush in there and use a spherical rod end. Unfortunately the drill keeps going blunt , and i have sharpened up several , i have used oil and a low speed also but no good. I take it this must be hardened, any ideas? do i heat it to shoften it?
 

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jeeez, get it done right by a pro.
 

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WTF! open it up with a die-grinder? drill etc...we dont live in the 70s anymore, get it machined right. Its a "forged" part, you cant heat shit like that up! Itll destroy the grain structure. (doesnt apply to stuff like rat rods etc that are limited to 56mph:incheek:)
 

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I'm Not Jed Clampett
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A Pitman arm will be a forging for sure. It'll probably be made from a medium carbon steel alloyed with something like Vanadium, which is what's giving your drill bit such a hard time. A TiN coated (Titanium Nitride - that gold colour) drill bit will live longer than a standard HSS drill on this type of steel.

Other thing is, how big a hole are you drilling and what speed are you using? it's not really possible to run big drill bits too slow, they just take longer to drill the hole. At 5/8" diameter on a tough material like this I'd try 60 RPM and rather than using oil, make sure to use a proper cutting fluid like this stuff CT-90 Cutting & Tapping Fluid 500ml Brand New! | eBay if you don't have any soluble coolant handy.

Sometimes drilling this type of component can just be tough going, I had to regrind a quality 1/2" drill bit 3 times while drilling some Chevy stub axles. If you are regrinding your own drills, grind the point so it has a small clearance which will allow you to put more pressure on the drill bit without it digging in or chipping the edge of the bit.

BTW, CT 90 should be a lot cheaper than the ebay price at J & L industrial/MSC if you have an account with them.
 

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Discussion Starter · #7 ·
cheers stueee i am only taking it out to 1/2 inch so not much rearly
i was running around 70rpm with a gold drill bit,
 
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