What size bit to use to bore the D-rings ?

I'm reffering to these D-rings

http://www.armysurpluswarehouse.com/product/rope-ring-with-clip-b21-5-for-500-3752.cfm


during the "Extra D-Ring mod".. Im going to use a friends drill press but need to provide my own bit.

 

I can't remember since I basically just matched one up to a bed bolt once I removed it, but I'm thinking 1/2"...

 

No need for all that, I just used the biggest bit I had and widened out the hole until the stock bed bolt fit while in the middle of my driveway.

 

That won't be quite big enough as the bolts have a section near the head that is wider than the threads. That's what keeps the washer captive. That's what I recall anyway.

If you don't have a set of drill bits, I'm pretty sure that 1/2" would do the job. I don't have any metal bits larger than that.

 

X2

I used mine for this but for the life of me can't recall the measurement I wound up using.

 

I managed to get them wide enough using a Unibit and didn't come anywhere near the top of the bit... it'll work.

Getting the washers off the bolt... that's a pain in the rear, but widening the hole in the d-rings is easy.

 

I didn't remove the washer. I ground one side of it flat to fit the D-ring and touched it up with some black paint. I bought an angle grinder a couple months ago and I'm really surprised how often I use it. If all I had was a hammer, I guess it would have looked like a nail.

 

I saw a write-up where the same thing was done (grind one side of the washer flat) and that turned out well. To your point, all I had was a hammer, a metal file and a vise (and a drill, and a step bit, etc but no grinder) so I got busy.

 

Inibit FTW

 

I got the washers off by setting the bolt head-down in a 27mm socket on the floor, washer resting on the rim of the sockert, then hammering the end of the bolt. There are no threads at the end, so no worry about dinging them. Reinstalled the washers after adding the D-rings by slipping an piece of pipe over the bolt and driving them back on.

I used OEM D-rings, took the plastic collar out and made some spacers from 1/2" id, 5/8" od tube to try to get the D-rings to swivel, like the ones at the rear. On tightening things down, the spacer bowed the big washer down into the hole in the bed, and the now-cupped washer caused the ring to bind, not swivel. Took out the spacer and will live with fixed position D-rings. Alternative would be to make longer spacers, but then the bolt head sticks up more than I want.