How Does One Peen Steel Rod?

I've been making a few deep reach clamps and have challenges retaining the steel pins where they pass through the wood (no problem with the one location they pass through steel). I've been using old bolts to make the pins, and they're somewhat variable in diameter, a few thousandths at the very least less than 1/4" ... the amount I've drilled the holes. My success at "enlarging" the ends to keep them from slipping through is not very promising.

Would steel rod be closer to the correct diameter? Would I be able to cut and then peen over hardened rod (W1, A2, etc)?

Probably hard to peen hardened steel. Why not just use cold rolled rod?
Bill

That was my concern. Probably should be asking on Practical Machinist where folks would actually have experience with this type of situation. I've been looking for 17/64ths" (anything slightly over .25") ... and there appears to be limited availability in 1018 cold rolled steel rod, but lots of availability in drill rod of various hardness schemes including oil hard.

You could make the pins from a drill blank. You would need a grinder to cut the pins to length.
17/64 (.2656) HSS Jobber Length Drill Bit Blank

For a lighter press fit:
Reamer Blanks - Letter Sizes Size: F (.2570"), OAL: 4-1/8" (2 Pcs.)

I would try the .257 pin first. The .265 might split the wood.

Some thoughts I might try. 1) make a slight countersink on both sides of the wood. Leave the pin a little long to be able to peen the end into the countersink from both sides. Have the pin over some metal on the bottom while you peen the top. File the excess flush with the wood. 2) use a center punch to "swell the ends" a little or 3) how about using a little epoxy glue to lock it into one side of the wood. You could put the epoxy in one side and the pin in from the other to keep it from getting on the parts you want to be free to move.

McMaster-Carr sells steel rod in various grades by the foot. You could also try brass or aluminum rod which would peen over easier.

Thanks folks for the various ideas. I ordered dowel pins from McMaster Carr. Says they are slightly oversize. In any event, it's a lot easier than cutting bolts and the price is very reasonable.

Nice clamps there! I'm not certain how much 'oversize' those McMaster dowels will be. Most likely only .0001's of an inch in my experience to aid in press fit to reamed holes in steel. They will probably fracture and or chip out rather than peen over also. I'd try some 1/4" cold rolled steel from say, Home Depot. They have it in a special project rack with flats and angle stock as well. Then, in some scrap, experiment with Letter Size B, C, or D drills to see which gives you the best interference fit with the steel rod. Chamfering the holes in the wood is a good tip. To aid in peening the ends into the chamfers, you need to relieve the centers of the ends of the pins. Try a #2 or #3 combination center drill to thin the ends of the pins. Then you can use a rounded over punch to expand the ends. I've done this numerous times with good results. If you want it to "look" better, relieve the ends 1/8* deep with a .250 ball end mill, then peen the ends into the chamfers.

I would recess a flat washer into the wood (epoxy) countersink a taper into the top. Then use cold rolled steel for the pins. Cut the pins a little long. Drill the top (a little), and peen / mushroom over and into the countersink. Flatten with a file until flush.

I would use 1/8 inch hot rolled steel, which is what Home Depot and Lowe's carries. Very malleable. I think 1/4 inch is overkill for those style clamps. The hot rolled is easily cut with a hacksaw if you don't have a grinder.

If you really did buy Dowel Pins don't even try to peen them. They are hardened. Bad things will happen including your language.
Bill

+1 on not peening the dowel pins. Drill rod is bought annealed,which means it is soft. Hoiwever,tool steel drill rods,even annealed is not the best thing to try peening. It soon work hardens as you are peening it.

Go,as suggested,to Lowe's or Home Despot(:)) and get some of the rod they sell. It is absolutely soft mild steel that will peen easily. Actually,a crummy grade of steel,but it will peen easily and be suited to your needs.

If you want something amazingly soft for peening,buy a box of black rivets. They have a head on one end. Be careful to get the type of head you want. Get them long enough to go clear through your wood and out the other side by at least 1/16". That rivet iron will peen like crazy. Personally,I'd just get the rod from Lowes.

What about using some heavy copper wire?

#16 nails with the heads cut off. Will easily peen. CHEAP!

Use Spring pings: http://www.mcmaster.com/#roll-pins/=xua4ul