Recessed holes in steel

[crosbike]

I need to make these bolts

sit flush with some steel plating i have. I have drilled the 3/8" hole for the shaft and tried using a 3/4 drill to match the taper of the bolt but its not working out too swell. Do they make countersink drill bits in a large size for steel? Or does anybody have any suggestions?

[crosbike]

i think i figured it out already.
http://power-tools.hardwarestore.com...it-655810.aspx

[Burton58]

yes they do make countersunk drill bits. the post above me shows where you can find them. listen to him

[Hydra]

I'm not sure, but you should review the above post

[Ktmracer419]

i was gonna do that for my crossmember. i bought a countersink for mild steel, got the bestest one there is at the local drill store (they specialize in it) used my drill press at extremely light pressure using cutting oil, and it still ended up chipping/ dulling the countersink. they sharpened it for me a few times but it never cut like new and i gave up on the idea.

right now i have bolt heads that oh so conveniently get sheared off. i'm going to modify it to run through bolts on the side of the frame though.

[crosbike]

i was gonna do that for my crossmember. i bought a countersink for mild steel, got the bestest one there is at the local drill store (they specialize in it) used my drill press at extremely light pressure using cutting oil, and it still ended up chipping/ dulling the countersink. they sharpened it for me a few times but it never cut like new and i gave up on the idea.

right now i have bolt heads that oh so conveniently get sheared off. i'm going to modify it to run through bolts on the side of the frame though.

Ya i wanted to recess the heads due to that reason of shearing the head off on a rock. I bought one at ACE and it happened to be for wood so it was useless. Ran to Home Guido and bought 2 3/4" countersinks. These have more cutting edges and reliefs to throw the metal away from the cutting edge so it works great. I just blasted through 15 holes with the use of a drill and cutting oil so im happy.

Going to do the other plate in a bit and bolt them up tomorrow when the bolts arrive.

[Ktmracer419]

they fuckin have them at the guido?

DAMMIT

[crosbike]

Ya I was shocked they had something I could use. It took me a bit to find them as they were under a display. 1 was about 9 bucks so i grabbed 2 just in case they blew chunks and i needed both of them to do what i needed. But they seem to work very well.

The one i used is made by eazypower, says isomax underneath and the# is 30062 for the 3/4" one i used. Worked great with my 3/8 bolt and matched the taper of the bolt head of 82* perfectly. Sits nice and flush.
http://www.eazypower.com/shop/