Gunsmithing Making a thread protector

[Kletzenklueffer]

My next project for machining class is to make a thread protector for my P226. I will likely make it out of stainless 303 or 304 since there is an abundance of suitable scrap pieces laying around.

So, I post here asking for tips and hints at how to do it. I talked to my instructor and he's game, so I have his expertise on tap, but I come to ya'll who have experience making them for the low down.

As I think about it, I come to two issues. Since it's going to be knurled, I figure I will need to run the bar stock with the knurling tool first due to the pressure applied. Then i figure I'll drill the inside diameter and ream to within min./max thread diameter, then thread with a boring tool. I figure if I want it, say .625" long, I need to drill and ream or bore to around 1" to give enough clearance for the boring tool.

Alternatively, I could do the above, and then just run a tap in to thread it. We don't have a 13.5mmx1 tap at school, so I can look for one.

How do you guys do it? Am I way off?

I haven't done any internal threading other than with a tap in the tail stock.

If it's simple enough, I'll do it tomorrow, otherwise the quarter is over until end of the month.

 

[BLAWTON]

Re: Making a thread protector

I have taps for all of them which make it really easy. I would suggest using a 416 stainless for ease of maching. Instead of knurling i prefer to use a indexing head in a mill and make a nut on the end of it. Good luck with ID threading hope you have a kick out on the lathe.

 

[Victor N TN]

Re: Making a thread protector

99% of the ones I have made are for rifle barrels that are transported as spares to matches and such. They are made from Delrin plastic and go on the receiver end of the barrel. The ones for the muzzle end I have made of stainless. I made a brass one that gets a lot of funny looks. Some with a hex nut cut like a nut on the end. I used a slitting saw and made like a big wood screw head on the end of one.

If you go ahead and thread the ID in a lathe, make you a run out groove in the back of it. It'll help with the ID threads if you don't have a lot of practice. Heck I do it anyway.

Good luck.

 

[BLAWTON]

Re: Making a thread protector

Yes +1 on the plastic or brass also. They will work just fine and do the job they were made for.

Note: Always cut a hole in the end of the protector that's going on the muzzle end.

 

[The Mechanic]

Re: Making a thread protector

+1 on Delrin
self lubricating
very strong
easy to machine
shock resistant
light in weight
multitude of colors
knurl-able
heat and cold resistant with little expansion and contraction
no galvanic corrosion or rust problems
resists embedding

 

[Kletzenklueffer]

Re: Making a thread protector

As indicated in the first of the post, this would be for a suppressed pistol, to protect the threads when the can is off.

I've had them for bolt guns as well. Typically the smiths made them from the barrel stub they cut off.

I see that Gemtech makes one like I need from aluminum for $20, but I want to make my own. I may do aluminum as well since there's no real function except to protect the threads.

One thing I've found is there are no 13.5mm LH taps on the whole planet (unless I have it custom made)

 

[Field]

Re: Making a thread protector

If they are LH threads then use a right hand internal threading tool and run the lathe in rev.. That way you cut from inside out and dont have to worry about stoping it in time, or use left hand tool in rev. for right hand threads.

 

[dukedurham]

Re: Making a thread protector

Sorry to jump in on the O.P., but, is Delrin really a good thing to use for a thread protector on a high power rifle?? I would have thought that the temps reached from a summer day of volume shooting might melt that thing like a candle...just wondering.(also a bit piqued because I need a TP for me new rifle as well)

 

[Aries64]

Re: Making a thread protector

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: dukedurham</div><div class="ubbcode-body">Sorry to jump in on the O.P., but, is Delrin really a good thing to use for a thread protector on a high power rifle?? I would have thought that the temps reached from a summer day of volume shooting might melt that thing like a candle...just wondering.(also a bit piqued because I need a TP for me new rifle as well) </div></div>
Don't mean to jump on you, but if you had bothered reading the thread you would have seen that the third post (posted by <span style="font-style: italic"><span style="font-weight: bold">"Victor N TN"</span></span>) mentions using Delrin as a thread protector material for the <span style="font-weight: bold">receiver end</span> of barrels being transported as spares. See the quote below for your reading pleasure:

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Victor N TN</div><div class="ubbcode-body"><span style="font-weight: bold">99% of the ones I have made are for rifle barrels that are transported as spares to matches and such. They are made from Delrin plastic and go on the receiver end of the barrel.</span> The ones for the muzzle end I have made of stainless. I made a brass one that gets a lot of funny looks. Some with a hex nut cut like a nut on the end. I used a slitting saw and made like a big wood screw head on the end of one.

If you go ahead and thread the ID in a lathe, make you a run out groove in the back of it. It'll help with the ID threads if you don't have a lot of practice. Heck I do it anyway.

Good luck. </div></div>

Keith

 

[JJones75]

Re: Making a thread protector

The SS will certainly hold up better if its gonna get banged up some but aluminum should be fine.

If its just a project for a class then I suggest you try some other internal threading first to get the hang of it rather than jump right in with a small metric hole.

when its done corretly it should look somthing like this.
NOTE : this work was done by Nathan Dagley of Strait Shot Gunsmithing

 

[dukedurham]

Re: Making a thread protector

Aries64- I DID read the thread, and as "The Mechanic" posted, he said that the Delrin was heat/cold resistant. "That" is what I was refering to when I posed my question. As to how resistant it is would give me the answer i was looking for. And you did mean to jump on me, go ahead and admit it, that's the first step for any 12 step program. Back to the original thread.

 

[dukedurham]

Re: Making a thread protector

Kletz- again, sorry.

 

[The Mechanic]

Re: Making a thread protector

I would not use it for shooting. However saying that, I have had bushings on race trucks I have made a driven that have held up to enormous stresses, as well as some mangled pieces from crashes that I have burned out with a torch and it took no less then 10 minutes with a LARGE rosebud to get it to burn out. I would imagine it would hold up just fine. I would prefer that fine piece of machine work JJones75 has shown however that is sweet.

 

[cav has been]

Re: Making a thread protector

Building one in delrin or aluminum as a first step would be good form. It will work short term,improve your skills,and be relatively inexpensive as far as materials and tools. I built several pieces out of aluminum before I duplicated them in Ti. Great teacher.

 

[badbot]

Re: Making a thread protector

I did delrin and only ran the tap about 1/8 out of the end giving the threads a internal taper allowing it to besemi self locking from friction.

 

[AJ300MAG]

Re: Making a thread protector

If I'm going to cut an I.D. thread I use a groove in the bore like Victor. I cut the threads in reverse with the tool upside down. That way I can start with the threading tool in the relief groove, the tool moves out of the hole (right hand thread) while cutting the thread and I don't have to worry about running into the shoulder inside the bore. Carbide threading bars are too expensive to crash!

 

[Kletzenklueffer]

Re: Making a thread protector

AJ- this is a LH thread I'm making, so it'll be from left to right anyway. Good point about turning the tool upside down. So do you cut on the back side then, or run the rotation in the reverse direction?

 

[AJ300MAG]

Re: Making a thread protector

The lathe would be run in reverse for a right hand thread. Your cutting a left hand thread so you'll be cutting from left to right anyways (if you run the lathe in it's normal direction of rotation).

If we were going to cut I.D. threads with a threading tool we'd line bore the hole to size after drilling. Thats the way I was taught.