Broken crank bolt

[RamAir95TA]

Did you even read about the Timeserts? The kit include everything you need to make the hole, including the proper size drill bit.

http://www.timesert.com/html/inchsert.html

Ugh.

[JGuy07]

Yes I did, but when looking them up the kits I was finding at the cheapest were still over $100....not an option for me. I couldn't find one for less let alone a decent distributor.

[guppymech]

Was under the impression the imprints on the taps indicated what size drill bit required. My 1/2 tap in the set I have has a separate set of stamped numbers reading 1/2" so I figured that was the drill size. I know there are different taps which require different things, but just made an assumption and guess I was wrong. So would I use the 29/64 bit to drill the new hole in order to use the 1/2" bolt? Can't seem to find that size anywhere around here since that was the size I was looking for when considering the inserts.

The tap I have is 1/2-20, and I guess I'll have to search more for the new bit.

Considering the consequences of ruining your crank I would recommend that you look into all the options out there, You're about to enter the school of hard knocks.

From the referenced tap and drill chart a 1/2 20 bolt takes a 29/64 drill. A 1/2 13 (course thread) bolt takes a 27/64 drill. Since you are having trouble finding a 29/64 drill bit, the next smaller bit is 7/16 which is .0156 smaller. In soft material I would try the 7/16 bit but the crankshaft is very hard material and I don't know if I would use it. The chart says 29/64 for a reason. You will need three 1/2 20 taps. A taper tap to start the threads, a plug tap to do the majority of tapping and a bottoming tap to finish threading to the bottom of the hole.

[RamAir95TA]

Considering the alternatives given your situation and timeframe to find a solution $100 seems pretty reasonable.

Hope your drilling/tapping works out okay. Good luck!

[JGuy07]

It isn't bad, I just don't have funds for it. Unpaid internships of over 40 hrs a week does that. Good advice though don't think that I'm not understanding, but it's just a route I can't go at this time.

The tap set I already have, and a drill bit of around $17 seems easier on the pocket atm. Just to clarify again. To use the 1/2" bolt I would need to use my 1/2-20 tap with a 29/64 drill bit? Thanks.