Knurling a bolt?

[okedoke]

please, someone tell Dick that pt&G HAS SOME 700 bolts on sale right now , OD = >699 - .709< price from 80$---125$, I can't sleeve, Knurl or bore the action for bushings any cheaper than just buying an oversize bolt. when you knurl metal you displace 50% of the bearing surface& leave many crators on the surface which in turn collects dirt, sand, etc.----- before you know it your back to square one------ take care Craig

 

[butchlambert]

Craig,
Plus 1 on your post.

 

[DickE]

OK I've been a bit busy, but I did a shaft that I turned down to .687 on my Lathe did a 20 tpi knurl on it, it came out to be .697. The shaft is not out of round, in fact quit the opposite, as I used the Grizzly floating knurling tool. I have sent for 22 tpi knurls as it should come out better for the diameter. Just thought some of you might like to see what a knurled bolt would look like. I have explained and shown a couple of people this, and they both wanted it done to their bolts. Time from chucking up in the lathe to finish is about half an hour.

 

[DickE]

Whoops, it somehow came upside down, but you get the picture.

 

[jscandale]

From time to time, I do some machining of large shafts that have a series of bearings for a steel fab plant near by. Very often I knurl the bearing race seats to provide just enough resistance for the race to stay put.
The idea of knurling a bolt is pretty neat and would certainly do the job. The only drawback that I could think of is that the knurling would hold various unsightly dirt, but still pretty cool.

JS

 

[boltfluter]

OK I've been a bit busy, but I did a shaft that I turned down to .687 on my Lathe did a 20 tpi knurl on it, it came out to be .697. The shaft is not out of round, in fact quit the opposite, as I used the Grizzly floating knurling tool. I have sent for 22 tpi knurls as it should come out better for the diameter. Just thought some of you might like to see what a knurled bolt would look like. I have explained and shown a couple of people this, and they both wanted it done to their bolts. Time from chucking up in the lathe to finish is about half an hour.

Dick,

Great job on the knurling. Very nice.

Regards,
Paul

www.boltfluting.com

 

[D-mon]

Hi,
On the subject of knurling, I recently did a job on a rifle where it did help me.
I have a ruger 77/22 rifle and I asked the local gunsmith to rebarrel it with a BSA international barrel I had in the corner of the workshop. I specifically asked for the barrel part that goes into the receiver to be of a very tight fit.
After the job was done I inspected it and could see a slight daylight gap between the top of the barrel shoulder and the top of the receiver ( when looking from the side). I decided not to worry and bedded the barrelled action into a stock, and shot the rifle at the range. I was a bit disappointed with the results, getting groups around an inch at 50 m and repetitive flyers.

I took the rifle back home and removed the barrel from the action. To my surprise the tenon was floating into the receiver!
So to cure that, I took carefully measurements of the action and barrel and set up the barrel in the the lathe. I knurled the tenon till I got the exact same dimension as the hole in the action.And now the barrel fits in the action with no lateral play whatsoever. I marked exactly where the barrel was going to index for the extractor position and I loctite it in place. Now that barrel is not going anywhere. I have tested the rifle again and now I have nice groups under 1/3 of an inch at 50 m and shot 3 magpies with it last weekend

So in this case knurling did help.

Nic

 

[okedoke]

I have to admit the knurling looks pretty good but so does the knurling job on a couple #50 lbs. dumbells i have in my shop plus a ratchet handle , a torque wrench etc.--- help I think I need a little help from Butch------- take care Craig

 

[butchlambert]

I agree with you again fellow Okie.

 

[ROCKJAG4]

did anyone really think this out real good??.when u knurl a pc. of metal it in fact looks like a file, . what do u think it is gonna do to the raceways of a soft action??. take a pc. with a real good knurl on it & rub it across the top of your action(if u dare) for about 100 strokes & then tell us what u find..

bad move. buy a new BOLT FROM KIFF..

 

[firearmdoc1]

+1 Rock, not to mention that the dirt, sand, grit and whatever else gets in there will act like a very course lapping compound which I am sure can't help things any.

 

[dmoran]

I only foresee advantages to knurling:
- tighten up clearance <> improved bolt alignment
- reduce surface tension
- like fluting, a place for debris to move into instead of wearing on the bolt and raceways, that can be easily cleaned out after the fact.

I will be having Dick knurl the back of my 700-bolts for the advantages to bolt alignment. Not only to the alignment to the cartridge cases, I also foresee pressure endurance to "bolt thrust", do to insured squareness of alignment of the bolt aft, to the lugs.

For 788-actions, I foresee a great way to clearance tighten the front of those sloppy aligned rear-lug bolts.

Thanks Dick for a cost effective innovative idea.......
Donovan Moran

 

[Ggmac]

Dont forget all knurling has been done on the softer of the 2 metals , bronze guides , alum pistons , etc NOT two similar metals , dirt , grit will ruin whatever temporary benefits you get . I use knurled bar stock to open up and line bore My custom actions , after heatreating ,not before as heatreating warps .

 

[dmoran]

Ggmac -

Why would you need to open up and/or line-bore custom actions?
After you line-bore, what do you do with the raceways?

Can't imagine why either would need to be done to a custom action. I have never heard the term "line-boring" of an action.
Donovan

 

[Ggmac]

I make them from steel billets , I make mine from scratch . Line boring allows me to get the fit I need , want , withe the tools I have .

 

[Concha]

How hard is the bolt body. It is heat treated chrome moly right. What...about 30 Rockwell?