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Plain ol Bill
10-19-2015, 10:09 PM
Guys what material would you use to make new pins for a Hossfeld bender? I'm looking for material that is tough enough in an annealed condition. I can heat treat if I need to using the forge and quenching oil but would have to draw back quite a bit to prevent any breakage. What do you recommend guys?

Toolguy
10-19-2015, 10:26 PM
I would go with 4140 pre hardened, sometimes called 4142. It's about 30 - 32 Rc. For reference 1018 CRS is around 10 - 12 Rc.

10KPete
10-19-2015, 10:27 PM
I like to salvage all sorts of stuff for different uses. For stuff like those pins I would use a chunk of axle shaft out of a
rear end unit.

Pete

paul463
10-19-2015, 10:53 PM
I used axle shafts from a front wheel drive car for a tube bender I built this summer. Never bothered to anneal it, just used carbide in the lathe and had no trouble.

macona
10-20-2015, 12:27 AM
Any steel will work just fine.

Dave C
10-20-2015, 12:29 AM
I used axle shafts from a front wheel drive car for a tube bender I built this summer. Never bothered to anneal it, just used carbide in the lathe and had no trouble.
I needed to make a two step adapter and was looking for a piece of round stock that was close to the larger diameter. Found a rusted axle in my scrap pile that was about the right size and cut a foot off of it with the band saw. Chucked it up in the lathe and proceeded to kill three carbide bits trying to turn off the splines before giving up and looking for some other material. The splined end of that axle was tougher than kelsey's nuts. Should be great for bender pins.

10KPete
10-20-2015, 03:19 AM
Yeah, the splines are hardened. But the rest of the axle isn't. I always cut off the splines and use the rest.

Pete

boslab
10-20-2015, 07:32 AM
You may be lucky and get some old chrome cylynder rod, found that stuff good for excavator bucket pins that last forever, machines ok with a tip but if you get the right OD then it's only a length cutting and sticking a washer on the end as a head
I have a bender, the pins are 18.8 bolts, works fine
Mark

Mcgyver
10-20-2015, 09:15 AM
any one of the common chrome molys....prehardened. Easy to machine and tough

gundog
10-20-2015, 10:57 AM
I always thought pins used for a shear strength application were better soft than hard like hitch pins they bend and deform when over loaded hard steel shears off when it fails. I am not an engineer just an old guy that makes stuff but that has always been my line of thinking. Hard materials are generally used when the part is in tension or compression not in a shear application.

Mike

Dave C
10-20-2015, 12:33 PM
Yeah, the splines are hardened. But the rest of the axle isn't. I always cut off the splines and use the rest.

Pete
You'd think after all these years I would have known better. I was in a hurry and my mind was in fast forward mode. Never a good thing.

Plain ol Bill
10-20-2015, 04:36 PM
Decided to go with 4140 material and ordered in some from Online Metals. Thanks guys.

Ries
10-21-2015, 04:44 PM
since you can buy brand new ones from Hossfeld or American Bender for between ten and twenty bucks, I wonder if you will save anything making your own- 4140 from online metals is not cheap, plus you gotta machine, or, in some cases, forge them, and heat treat them.
I have broken ONE hossfeld pin in the last 35 years, and a nice new one cost ten bucks back when I did that.
Seems like a case where economy of scale means you will pay more, even if you dont value your time as being worth anything.

crazypj
10-21-2015, 05:12 PM
Anecdote just for the hell of it ;)
Back in the mid 70's when I was training, we had a marine engineer as an instructor.
He worked out that 1" diameter 4140 (It was British EN numbering, I forget the exact one) had around 120 ton single shear so the 5/8" pins I was making (in double shear) were way more than I could break.
I took his word for it and never had a problem

LARRYR
10-21-2015, 05:44 PM
i have used grade 8 bolts for years on my hossfeld no2. 3/4 bolts long enough to work can sometimes be hard to find, but over the years i have accumulated a good supply. i weld u straps onto the heads to make easy pulling. i have never tested any of the original hossfeld pins but they file easy so i suspect they are nothing special. because most of the tooling spans the complete opening of the machine the forces applied to the pins are mostly shear, and i don't think you can do anything on a hossfeld to shear even a mild steel pin. i have used my machine with hyd's to bend 1 3/4 chromemoly tubing with no problems. these machines last forever. thats why there are so many copies out there.

Ries
10-22-2015, 05:24 PM
i have used grade 8 bolts for years on my hossfeld no2. 3/4 bolts long enough to work can sometimes be hard to find, but over the years i have accumulated a good supply. i weld u straps onto the heads to make easy pulling. i have never tested any of the original hossfeld pins but they file easy so i suspect they are nothing special. because most of the tooling spans the complete opening of the machine the forces applied to the pins are mostly shear, and i don't think you can do anything on a hossfeld to shear even a mild steel pin. i have used my machine with hyd's to bend 1 3/4 chromemoly tubing with no problems. these machines last forever. thats why there are so many copies out there.

You might not be able to "do anything" to one, but I have sheared one. And I am no Arnold Schwarznegger, either. The whole point of a hossfeld is mechanical advantage, and, if it can bend 1/2" x 3" flat bar, it can certainly bend 3/4" round.
It was one of the ones that is forged down to a rectangle for the last 3/4" or so, and I was bending on top of the frame, so the load was uneven, and at the point where the material already had stress riser issues due to the forging, but I snapped that puppy right off. And it didnt break like A36 mild steel. My guess is that its a slightly higher carbon, probably not 4140, and that it is, indeed, heat treated.
I work out a hossfeld harder than most people, admittedly- but I can assure you, it is possible to break them, and also to wear the holes oval in the frame- I have had to replace my frame, after about 25 years of use.
I have used plain old mild steel shop made pins, and also a piece of 304 stainless, and been able to bend both- I dont use em anymore, as they are not as strong as the factory pins.