Drilling bolt, looking for advice

[jperry1290]

Trying to drill out a grade 5 bolt to 1/8in for my trac bar riser cotter pin. I bought an Irwin colbalt drill bit and it doesn't do anything. I drilled slow with cutting oil and it just spins . Should I even try to buy another brands bit?

 

[BanditBronco]

Honestly, I would just order the correct bolt with the key hole and save yourself the year of life you will lose by trying to drill it. I would bet McMasterCarr will have it, they are usually next day shipping as well. Or you can try www.specialty-fasteners.com, solid mid-cal small business with really quality hardware.

 

[jamesroney]

Trying to drill out a grade 5 bolt to 1/8in for my trac bar riser cotter pin. I bought an Irwin colbalt drill bit and it doesn't do anything. I drilled slow with cutting oil and it just spins . Should I even try to buy another brands bit?

Yes, go get another drill. Grade 5 bolts are fairly soft, and easily drilled using high speed steel twist drills. People often damage the cutting edge when starting the drill on the threaded portion of the bolt. There are countless thousands of grade 5 bolts drilled for safety wire and people do it every day.

You will find that if you take a small die grinder and make a flat spot in the location that you want your cotter pin hole...then it is much easier to start your pilot hole, and you won't damage the cutting flute.

 

[Rustytruck]

get a good 1/8" drill bit and this time run it fast and push it through running it slow and dragging the bit just wears it out by heat and work hardening the surface. grinding the spot to start helps too. just dont baby it. please wear safety glasses.