hardened and ground bolt

Got pix?

Shoulder screws look like socket-head ground dowel pins, with threads a size smaller than the shank.

Grade 8 bolts can be machined to a very smooth finish with HSS.

Wes

Shoulder screw, as Wes and Jim mentioned, if you can get away with coarse threads. Keep in mind that shoulder screws are not awfully hard (

"shoulder bolt"

Google is your friend

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No, neither of these will work. The tightening of the bolt is what holds the hook and shear together. There is "A LOT" of force here, over 1000 lbs. on the pushrod to the shear plate. Its got to be one piece. The fine thread adjustment is finicky enough, coarse threads would be terrible.

I know McMasterCarr don't have it. The Fastenall store near me is run by idiots. I'll go to Fastenal when I get to the cities sometime.

Karl

Maybe the question would be what tool steel and heat treat schedule would work in this application. I've never seen fine thread shoulder bolts, not that me not seeing any means much.

Re-reading things, you need the bearing diameter and major diameter of thread to be the same. I should have paid a bit more attention.

I think we are talking DIY.

Wes

I'm afraid so too, but I want to double check. If I fire up the CHNC for this job, I'll make a hundred or so. So, what material are roll pins made of? And, what's the heat treat parameters?

Karl

Get a shoulder or die bolt a litttle longer and turn and cut a new fine thread on turned down end.

John

Also called a "stripper bolt".

Go to MSC's site and look up their part number "67656827" for one sort of close. Here's the description:

====================================================================== Socket Head Stripper Bolts - Alloy Steel Convenience Packs Type: Stripper Bolts/Shoulder Screws Shoulder Diameter: 1/2 Shoulder Length:

I suspect that the shoulder length is too long for you, but this was the first which I stumbled across with 1/2" shoulder diameter and 3/8" threaded section (3/8-16).

Enter "stripper bolt" in the search tool for a more complete list, and have fun wading through those to find what is closest.

Good Luck, DoN.

Use a lock nut and a spring washer to keep tension on the 2 pieces. with a drill bushing and thru bolt. Then the adjustment is not as critical.

Not a shoulder or stripper bolt, per Karl's original. Threaded portion and ground portion are same diameter. I looked for a while, couldn't find one like that. They probably exist, but who knows where. Were it me, I'd hit my favorite fastener vendor and see what they could come up with.

Otherwise, it looks like he'll have to make one. It might save a lot of work if he could figure out how to make and fasten the head onto O-1 or A-2 ground stock. Just thread as needed before heat treat.

Shoulder bolts are intended to provide a fixed length "axle" for a rotating tooling component. I gather that Karl's application requires tension adjustment for the pruner jaws, hence the same diameter fine pitch threads.

Pete Keillor

Pete Keillor