Colorado Pete
Member
- Joined
- Dec 7, 2004
- Messages
- 6
I made a few Mauser .22LR screws which are no longer available from any parts source. After the first experimental attempt, the results were very good.
Everyone with a home shop can make very good reproduction screws by using a drill as a lathe, some files, and the proper die to thread. In this instance I made the receiver screws for a "Suhl Waffenstadt" DSM-34 rifle.
I started by examining the original and measured everything including the thread pitch, verifying that all measurements made were metric and that the funky shoulder is not for the std 82 degree countersink version of US screws, but is 90 degrees--then made a shop drawing. DSM-34, KKW, and MAS-45 screws are all M6x1.0. Jon Speed's Mauser Smallbores book didn't have any screw specifications. I now have a crude CAD drawing if anyone wants one. [Send me an email at [email protected]]
I selected a piece of 8mm round stock (the thickness of the screw head) and chucked it into a drill. Secure the drill in a padded vise. You now have an improvised lathe.
Make sure you have at least 50mm sticking out because the shank length will need to be 38mm. Use a sharp needle file and cut the 45 degree shoulder near the chuck first. Then cut the shank on the right down to 6mm (.236"). Be careful and measure often. If you use a wider flat file you'll get more even results. And you get better results with a smooth cut file than a bastard file.
Don't press hard on the metal stock with the file--let the file do the cutting work. The bearing of the drill won't like the additional abuse and you'll shorten the life of your drill motor. File lightly and take more time.
When the shank is 6mm all the way across, stop filing. Get some wet/dry emery cloth and polish the shank with progressive grits down to 400 to remove the file marks.
With the screw still in the drill, apply Dykem Blue to the shank, measure and mark the correct length - in this case 38mm. Cut the shank to length. The overall length (OAL) of the rear tang screw is 40mm. [NOTE: If you are making the front DSM-34 screw, they are shorter with a 35mm OAL with a 33mm shank length] Slightly chamfer the ends of the shank with a file--it will make threading with a die easier later.
Cut the screw off about 2mm above the 45 degree shoulder to leave material to shape the head.
Reverse the screw in the drill--the head and shoulder of the screw are now sticking out of the chuck. Use the file to shape the oval head. The head and shoulder combined should only be about 2mm high for Mauser screws. Polish again with emery cloth and you should now have the completed screw blank - it should look exactly like the screw you're trying to make.
Remove the screw blank from the drill.
In a leather padded vise or between two blocks of wood, secure the screw blank in the "head up" position. Take a hacksaw and carefully cut the slot. A new hacksaw blade is about .030" wide. Start with a single LIGHT cut. Look at the cut, if it's NOT centered, place the saw back into the groove and turn the saw blade clockwise or counter-clockwise until it looks centered and make another light cut in the correct place. Check it again and if the slot looks centered, start cutting the slot to HALF of the slot depth. Turn the screw and cut the slot from the other side. Ensure the slot depth is even on both side of the screw. You don't need to own those nifty $27 screwhead files, just be careful and take your time.
Now you cut the threads. Turn the screw shank up in the vise and secure it. Cut the threads. In this case I purchased a 6mmx1.0 die. Only cut threads for the first 11mm of the shank, no farther. Remember to use cutting fluid for smoother thread results.
You should now have a completed screw "in the white". Clean the screw in solvent with steel wool.
Take the screw to your propane torch and heat to cherry red. Quench in light motor oil - I use 10W. This will harden and heat blue your screw at the same time.
Total time: 1.5 hours.
Other thoughts - if you are making "fillister" type screws - such as the older Mauser Es340N. They are M5x0.8 size. Use pillar files with a safe sides. They will make sharper shoulder corners between the head and shank. The die for these threads are also commonly available at hardware store.
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Process change 1:
After cutting the shank to the proper length (38mm in this example), chamfer the ends of the shank with a file for threading. Remove the rod from the drill chuck and secure it shank up in a vise. Make sure the drill rod is prependicular by using a square.
Cut the threads using a die/diestock.
Remove the rod from the vise. Back to the drill...reverse the screw in the drill.
The head and shoulder of the screw are now sticking out of the chuck.
Cut the screw off about 2mm above the 45 degree shoulder to leave material to shape the head.
Use the file to shape the oval head.
Continue as above.
Everyone with a home shop can make very good reproduction screws by using a drill as a lathe, some files, and the proper die to thread. In this instance I made the receiver screws for a "Suhl Waffenstadt" DSM-34 rifle.
I started by examining the original and measured everything including the thread pitch, verifying that all measurements made were metric and that the funky shoulder is not for the std 82 degree countersink version of US screws, but is 90 degrees--then made a shop drawing. DSM-34, KKW, and MAS-45 screws are all M6x1.0. Jon Speed's Mauser Smallbores book didn't have any screw specifications. I now have a crude CAD drawing if anyone wants one. [Send me an email at [email protected]]
I selected a piece of 8mm round stock (the thickness of the screw head) and chucked it into a drill. Secure the drill in a padded vise. You now have an improvised lathe.
Make sure you have at least 50mm sticking out because the shank length will need to be 38mm. Use a sharp needle file and cut the 45 degree shoulder near the chuck first. Then cut the shank on the right down to 6mm (.236"). Be careful and measure often. If you use a wider flat file you'll get more even results. And you get better results with a smooth cut file than a bastard file.
Don't press hard on the metal stock with the file--let the file do the cutting work. The bearing of the drill won't like the additional abuse and you'll shorten the life of your drill motor. File lightly and take more time.
When the shank is 6mm all the way across, stop filing. Get some wet/dry emery cloth and polish the shank with progressive grits down to 400 to remove the file marks.
With the screw still in the drill, apply Dykem Blue to the shank, measure and mark the correct length - in this case 38mm. Cut the shank to length. The overall length (OAL) of the rear tang screw is 40mm. [NOTE: If you are making the front DSM-34 screw, they are shorter with a 35mm OAL with a 33mm shank length] Slightly chamfer the ends of the shank with a file--it will make threading with a die easier later.
Cut the screw off about 2mm above the 45 degree shoulder to leave material to shape the head.
Reverse the screw in the drill--the head and shoulder of the screw are now sticking out of the chuck. Use the file to shape the oval head. The head and shoulder combined should only be about 2mm high for Mauser screws. Polish again with emery cloth and you should now have the completed screw blank - it should look exactly like the screw you're trying to make.
Remove the screw blank from the drill.
In a leather padded vise or between two blocks of wood, secure the screw blank in the "head up" position. Take a hacksaw and carefully cut the slot. A new hacksaw blade is about .030" wide. Start with a single LIGHT cut. Look at the cut, if it's NOT centered, place the saw back into the groove and turn the saw blade clockwise or counter-clockwise until it looks centered and make another light cut in the correct place. Check it again and if the slot looks centered, start cutting the slot to HALF of the slot depth. Turn the screw and cut the slot from the other side. Ensure the slot depth is even on both side of the screw. You don't need to own those nifty $27 screwhead files, just be careful and take your time.
Now you cut the threads. Turn the screw shank up in the vise and secure it. Cut the threads. In this case I purchased a 6mmx1.0 die. Only cut threads for the first 11mm of the shank, no farther. Remember to use cutting fluid for smoother thread results.
You should now have a completed screw "in the white". Clean the screw in solvent with steel wool.
Take the screw to your propane torch and heat to cherry red. Quench in light motor oil - I use 10W. This will harden and heat blue your screw at the same time.
Total time: 1.5 hours.
Other thoughts - if you are making "fillister" type screws - such as the older Mauser Es340N. They are M5x0.8 size. Use pillar files with a safe sides. They will make sharper shoulder corners between the head and shank. The die for these threads are also commonly available at hardware store.
---------------------------------------------------------------------
Process change 1:
After cutting the shank to the proper length (38mm in this example), chamfer the ends of the shank with a file for threading. Remove the rod from the drill chuck and secure it shank up in a vise. Make sure the drill rod is prependicular by using a square.
Cut the threads using a die/diestock.
Remove the rod from the vise. Back to the drill...reverse the screw in the drill.
The head and shoulder of the screw are now sticking out of the chuck.
Cut the screw off about 2mm above the 45 degree shoulder to leave material to shape the head.
Use the file to shape the oval head.
Continue as above.
