Threading grade 8 bolts?

[Jason280]

I have some 8" grade 8 bolts in 7/8-9 thread pitch, and need them to be threaded the full length of the shaft. Is it possible to run them through a standard 7/8-9 die, or will they be too "hard" for a standard die?


eta: Here are a few pics:

http://www.garagejournal.com/forum/showthread.php?p=4465589#post4465589

 

[A_Pmech]

The bigger problem is modern bolts are roll formed. That means the diameter of the unthreaded portion of the bolt is substantially smaller than the minimum major diameter for the thread size of the bolt.

Edit: Forgot to mention that full thread bolts are available to at least 6", probably longer.

 

[Dick in Wisconsin]

Jason ... isn't that a roll former in your picture?

Seriously, I think you can special order those. What is your application?

 

[Jason280]

I'm going to start another thread with pics, but I snagged 5 aluminum jack stands today, and they all use a 7/8" bolt and threaded rod. I was hoping to use the bolts to make different style brackets to fit in them, as only one actually had the threaded rod in place..

 

[Dick in Wisconsin]

I don't think you need to start another thread, add the pics to your original post as an edit.

Since you don't need a thousand of them, check with ARP ... they make high quality fasteners for motorsports applications. You might pay a premium, but you could find just want to you want.

http://arp-bolts.com/

Another suggestion is to contact the manufacturer(s) that you see at the hardware store directly. They might already make what you're looking for.

I think grade 8 is going to be pretty hard to try to cut with a die. Have you considered putting them in a good lathe?

 

[benzoni]

Never have with 7/8 bolt but have with multiple other grade 8 bolts. Dont see why it shouldnt work.

 

[Jason280]

I may be better off simply sourcing 7/8-9 threaded rod, and cutting it to length.

 

[A_Pmech]

Grade 8 threaded rod is available from McMaster.

 

[Eds_tls]

Grade 8 is too hard to cut with a hand die

 

[kingston]

You will ruin the bolt. The cut threads will not yield the same as the roll formed threads. Get the correct bolt.

 

[T45]

You will ruin the bolt. The cut threads will not yield the same as the roll formed threads. Get the correct bolt.

Yeah, you cannot make your own bolts...I learned that the hard way as well trying to make a special from a 12.1 socket head.

Basically, the options noted above are correct--either order one from a manufacturer/industrial supply or use threaded rod and cut it. Be mindful to not wreck the heat-treatment if you decide to go the latter route.

 

[xela456]

7/8 all-thread. cut to length and weld a nut on the end

 

[404]

7/8 all-thread. cut to length and weld a nut on the end

Or epoxy the nut, JB Weld.

 

[MaineGuide]

Your local Fastenal can probably help you out. They call them 'tap bolts' for whatever reason.

 

[mixerfixer]

www.mscdirect.com is where we source alot of off the wall stuff. Most times way more cost effective over Grainger

 

[larry_g]

http://www.mscdirect.com/FlyerView?pagelabel=2046&search=04352936&contentPath=/sales-catalogs/big-book

The above link is for a 8.5" long stud. Msc also has alloy threaded rod. Look around the few pages in the catalog before the studs.

lg
no neat sig line

 

[rusty65]

The bigger problem is modern bolts are roll formed. That means the diameter of the unthreaded portion of the bolt is substantially smaller than the minimum major diameter for the thread size of the bolt.

Edit: Forgot to mention that full thread bolts are available to at least 6", probably longer.

I do that all the time use a die to thread deeper on the bolt I don't know but I've never once had a issue and I have done it a number of times.


Sent directly from the Snap On Kool Aid factory.

 

[Outlawmws]

Tomorrow, the odds are good one that you did it to will fail in the worst or most embarrassing way possible!

 

[BDT/NWMN]

I have bought 7/8" and 1 1/8" Grade 8 threaded rod in six foot lengths for similar uses.. Also,,, I favor using the "H" or heavy nuts that use a larger wrench size.... Acme threaded rod would be even better..

 

[Adam.C]

Never have with 7/8 bolt but have with multiple other grade 8 bolts. Dont see why it shouldnt work.

You could add threads to age 8 bolt, but the bolt won't be gr 8 when you are done. Better to buy the quality bolts you need for your application.

 

[Danglerb]

I'm going to start another thread with pics, but I snagged 5 aluminum jack stands today, and they all use a 7/8" bolt and threaded rod. I was hoping to use the bolts to make different style brackets to fit in them, as only one actually had the threaded rod in place..

Picts would really help out. I get the feeling we could all be carefully advising you how to do what you want, but that what you want might be totally wrong.

 

[Ed ke6bnl]

Grade 8 is too hard to cut with a hand die

they do cut easily but may be weaker the the threads already there

 

[dnschmidt]

Haven't you ever heard of McMaster-Carr the source of all things good?

 

[benzoni]

Somehow I missed the part about what you were doing with the rods and the pics. I would advise against using anything homemade when it is critical to your safety, as in jackstands.

 

[Outlawmws]

That would depend on who is making it, wouldn't it?

 

[theoldwizard1]

The bigger problem is modern bolts are roll formed. That means the diameter of the unthreaded portion of the bolt is substantially smaller than the minimum major diameter for the thread size of the bolt.

I have "extended" the threaded area of a grade 5 bolt. That was a pain in the **** !

 

[ss454]

running a die down grade 8 bolts and having them look great is easy, is the grade 8 hardness/stength still there?

 

[benzoni]

That would depend on who is making it, wouldn't it?

Yes, yes it would.

 

[Jason280]

I believe I am simply going to go with a piece of threaded rod, then weld on brackets. I've found the rod fairly cheap at Tractor Supply, surprisingly cheaper than it can be ordered (which is rarely the case). As I've mentioned in the other thread, I would like to set them up as axle stands, which would keep them off the ground in my shop. Great thing is, the extra one can keep the pinion level, which will make it easier when I build the next 8.8 for the Jeep.

 

[Scsmith42]

Are you sure that the Tractor Supply all-thread is grade 8? Most threaded rod is grade 3 and sometimes 5.


Scott

 

[Jason280]

It has that "zinc-silver" look, so I would assume its grade 3. I know all of their G5 nuts/bolts are black, whereas the G8 is all golden urine yellow.

 

[mopar65]

should be able to go to your local Fastenal store and get what you need