how do I get/make rollers for weld coupon test bender

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Hi All.I plan on building a weld coupon bend tester, similar to the attached diagrams and photos.  how can I get or make the rollers?1.  Can I buy the two rollers “off the shelf”?  (this would be easiest approach i think).  i cannot locate a seller.  i think they should be hard steel.  They need to be at least 1.75 inches long (since the coupon width will be 1.5 inches.  Can you tell me where I can buy these?  Roller diameter should be 1.5 inches, or more.  I searched for a seller without success.2.  If these rollers cannot be purchased, how would you make them?  I am thinking 4030 steel tube cut to 1.75 inch length.  I do not have a lathe or way to machine them.  do i buy a bushing that goes between the steel tube and a bolt?  would it need to be a tight fit?  or would a loose fit be okay?  where to buy bushings?  what type?  solid brass?  or should i use needle bearings inside a tube?  i have never done bearings before.i know i could weld in some fixed non-rotating “rollers” on the shoulders of my fixture (such as wrist pins, or solid rod), but i prefer to utilize rollers that will actually rotate.i am hoping you can help me find where i can purchase rollers, or how to make rollers. any ideas or advice would be appreciated. thanks. Attached Images
Reply:No idea if this will help, but for my work (conveyor repair-commercial) Omni Metalcraft makes our rollers and pulleys.https://omni.com/products/conveyor-rollers/They custom make just about anything we come up with. Wall thickness, diameter, length, axle size, bearing type, etc.If a roller won't work, possibly one of their pulleys.Yeswelder MIG-205DS(3) Angle Grinders at the ReadyJust a hobbyist trying to improve
Reply:[QUOTE1.  Can I buy the two rollers “off the shelf”?  (this would be easiest approach i think).  i cannot locate a seller.  i think they should be hard steel.  They need to be at least 1.75 inches long (since the coupon width will be 1.5 inches.  Can you tell me where I can buy these?  Roller diameter should be 1.5 inches, or more.thanks.[/QUOTE]     some dom tube w/ a bolt for shaft.    i got some dom thats perfect for that.     its ur 1.5"od, its got a .237 or .243 wall or something like that, so its got a lil clearance for a 1" bolt w/ a dab of grease on it.   i got some 1.5" in .250 wall also, so if bolt shank is a couple thou under, it might be good too.     u dont need hardened, buy a couple feet of dom, and ur set for life.        " hangtown", yeaLast edited by 123weld; 05-18-2021 at 01:45 PM.
Reply:123weld:"some dom tube w/ a bolt for shaft. i got some dom thats perfect for that. its ur 1.5"od, its got a .237 or .243 wall or something like that, so its got a lil clearance for a 1" bolt w/ a dab of grease on it. i got some 1.5" in .250 wall also, so if bolt shank is a couple thou under, it might be good too. u dont need hardened, buy a couple feet of dom, and ur set for life. " hangtown", yea"sounds like your 1.5 outer diameter tube with .243 wall would work good.  (to show my ignorance, if i got your 1.5 tube with .250 wall, i don't know if 1" bolts are sold at under 1" or only at exactly 1").  let me check with McMaster carr on what diameter their 1" bolts have, and i will get back to you.  i am definitely interested in your suggestions, and appreciate your feedback.
Reply:Pretty much anything should work, just need the rounded corners. If your welds are good they won't crack or break. Tech school had a press in every lab. They pushed the coupons right through with a bit of a bang when they popped through.
Reply:Originally Posted by opa123weld:"some dom tube w/ a bolt for shaft. i got some dom thats perfect for that. its ur 1.5"od, its got a .237 or .243 wall or something like that, so its got a lil clearance for a 1" bolt w/ a dab of grease on it. i got some 1.5" in .250 wall also, so if bolt shank is a couple thou under, it might be good too. u dont need hardened, buy a couple feet of dom, and ur set for life. " hangtown", yea"sounds like your 1.5 outer diameter tube with .243 wall would work good.  (to show my ignorance, if i got your 1.5 tube with .250 wall, i don't know if 1" bolts are sold at under 1" or only at exactly 1").  let me check with McMaster carr on what diameter their 1" bolts have, and i will get back to you.  i am definitely interested in your suggestions, and appreciate your feedback.
Reply:A very nice How-To from the fine folks over at Weld.com crew.
Reply:A very nice How-To from the fine folks over at Weld.com crew.
Reply:Hf pipe bender would be easily modifiable.  Only need an upper die.
Reply:The ornamental bender at HF has multiple sizes of the rollers you need. I know 7 ish years ago they were at least case hardenedSent from my SM-G960U using Tapatalk
Reply:OP here. i have questions i need help on. i built a bend tester fixture, and i built a plunger that will press down on my welding coupons so i can bend test them.attached are two photos. they will be used with a hydraulic press.I used 4140 for the plunger. it came from McMaster carr and is annealed (i believe it presently has a rockwell c hardness of RHC 10). I welded the 4140 to a bar of 1018 mild steel (i used 312 tig rod). I will mount the plunger on my hydraulic press. but before i install it:questions: 1. should i use the 4140 plunger "as is"?2. should i first heat treat the 4140 plunger (heat to austenitize and then quench ( in oil? in water?) and then temper it ?3. should i "case harden" the 4140 plunger with Cherry Red "instant hardening compound" powder instead of heat treating it ?i have never heat treated or case hardened steel before.my thoughts: the plunger is probably hard enough "as is" since it already has chrome-moly and .40 % carbon. but i would like to see what you all think. thanks for your feedback. Attached Images
Reply:If you aren't testing a lot of items, plain cold rolled 1018 or so is just fine. So you will be ok.If your a weld testing school, a tool steel would be best as you would want to wear out your tester on someone else's coupon.Maybe change your bolts to grade 8 or 12 depending on thickness, bug I would have made the bolts at least 3/4"Sent from my SM-G960U using Tapatalk
Reply:It simple with little machinist back ground.I would look at bolts it simple and can done with out a lathe.Dave  Originally Posted by opaHi All.I plan on building a weld coupon bend tester, similar to the attached diagrams and photos.  how can I get or make the rollers?1.  Can I buy the two rollers “off the shelf”?  (this would be easiest approach i think).  i cannot locate a seller.  i think they should be hard steel.  They need to be at least 1.75 inches long (since the coupon width will be 1.5 inches.  Can you tell me where I can buy these?  Roller diameter should be 1.5 inches, or more.  I searched for a seller without success.2.  If these rollers cannot be purchased, how would you make them?  I am thinking 4030 steel tube cut to 1.75 inch length.  I do not have a lathe or way to machine them.  do i buy a bushing that goes between the steel tube and a bolt?  would it need to be a tight fit?  or would a loose fit be okay?  where to buy bushings?  what type?  solid brass?  or should i use needle bearings inside a tube?  i have never done bearings before.i know i could weld in some fixed non-rotating “rollers” on the shoulders of my fixture (such as wrist pins, or solid rod), but i prefer to utilize rollers that will actually rotate.i am hoping you can help me find where i can purchase rollers, or how to make rollers. any ideas or advice would be appreciated. thanks.
Reply:Just stack however many bearings you need to make width on a bolt. Find a bearing with  correct outside diameter, say it is 1/2" thick, you need 4 of them on the bolt to make a 2" roller...