Looking for S&W 1917 .45acp hand torsion spring

lfmayor · December 14, 2008, 01:53 AM

Does anyone have a hand torsion spring for sale? I have a model 1917 .45 acp Smith and Wesson DA that I had apart to duracoat and I managed to wreck the hand torsion lever spring while removing it. My pistol is an early model without the hammer block safety.

This is a flat spring that rests in a slot cut on the inner side of the sideplate, in operation it provides positioning force on the hand as it reciprocates (as the hand indexes the cylinder).

I'm having a bear of a time finding one, been to Brownell's, Numrich, Sarco and can't locate one.

Thank you,
Rich

**Unclenick** · December 14, 2008, 01:26 PM

I don't know of a source off-hand, but perhaps S&W would either have one or could refer you to some folks who might? A S&W collectors association is another possible source.

The last resort is to make one. If you have the mangled one and any pieces that may have snapped off to measure, that can be done. Flat spring stock is available at Brownells. The limitation is that it is all 1/16" or 1/8" thick. Enco sells it between 2 thousandths and 1/32" thick. Borwnells also sells an AGI book on making flat springs. I suppose that is being resorted to more frequently these days. Dremel cutoff wheels will do the carving, but spray a little water or oil on first to keep the heat down.

salvadore · December 14, 2008, 03:07 PM

Mine broke years ago, never knew what it was until now. Does your gun still work?

lfmayor · December 14, 2008, 05:57 PM

I appreciate the help folks... never even crossed my mind to talk to a collectors group, I'll search some up online.

Sal... yes, everything still works, except that I have to manually index the cylinder. This was an old Bolivian (I think) that had the fancy unit and government marks, the finish was in real bad shape. I liked the way it shot, the bore didn't look all that great but it hits where you point it.
When the mainspring failed and while I had it apart I decided to Duracoat it. It looks great now, in woodland tan, except for the manual indexing

.

UncleNick... I'll try and build one out of last recourse, this spring has some "funny" shapes in it and it might be a real bear to try to duplicate, it looks like a ton of hand filing. Do you just heat to a cherry red and oil quench to make a spring?

I'll get her right again, the pistol just has a good feel to it, pointability I'll call it.

salvadore · December 14, 2008, 07:27 PM

The reason I asked is because my brazilian surplus 1917 still works just fine. It is the most accurate shooter I own.

Bill DeShivs · December 14, 2008, 08:55 PM

Heating spring steel to red and quenching HARDENS the metal. You must then polish and TEMPER the spring by heating it to just past blue. Let it air cool.
If the spring is small, you can temper in a toaster oven at 450-500 degrees.

**Unclenick** · December 14, 2008, 09:40 PM

The basic process for 1075 spring steel is to heat it cherry red and quench it in oil, which renders it "dead hard", then to reheat it to draw it back (tempering). 500°F is one temperature that is used for this. It leaves the steel springy, but a bit brittle. Another temperature drawing range is 750°F. This leaves the spring slightly maleable, so you can bend it a bit, though it is more prone to taking a set than the lower tempered spring.

Under no circumstance use a temperature between 500°F and 700°F to draw the spring. That is the temper embrittlement range for common carbon steels. If drawn back within that range, the steel not only loses tensile strength, as normally occurs as the drawing temperature is increased, but at the same time it actually becomes more brittle than it was at 500°F. By about 700°F the ductility has returned to what it was at 500°F, and tempering at higher temperatures from that point upward continues the decrease in tensile strength and increase in ductility. Note this only applies to conventional carbon steels. Other alloys can have different temper embrittlement ranges. 416 barrel steel, for example, has a temper embrittlement range that is something like 700°F to 1100°F, IIRC.

The old fashioned method was to quench the spring in motor oil, then hold the oily piece in tongs while you set it on fire. The oil fire would bring it up to the lower temper range. The problem is that while that works OK on a heavier flat spring like a mainspring for a flintlock, it can overheat a thin spring.

The rolled flat spring stock at Enco will already be heat treated for cut and paste spring making. You cut it and form it, like music wire. It is the higher temper (temper comes from the same root as temperature, so "high" temper means softer and more ductile and "low" temper means harder and more brittle).

Here is a link to some spring tempering information.

James K · December 14, 2008, 11:34 PM

Hi, lfmayor,

All good advice, but unfortunately all based on an erroneous idea.

The hand spring in a 1917 is a coil spring that sits in a hole in the front of the trigger and operates the hand through a pivoting lever that is pinned into the top of the trigger. If the hand does not have tension the hand lever may be missing, bent or not engaged, the hand lever spring may be missing or damaged, or the small pin in the hand may be broken or bent. But the spring in the sideplate has nothing to do with it.

Now to that spring in the sideplate. That is an early version of a hammer block. It is its own spring and is designed to be pushed back into the sideplate by the cam surface on the hand. That way, the firing pin cannot reach the cartridge unless the trigger is pulled. But if the spring breaks or fails, the hammer block won't work and a hard enough blow on the hammer will set off a round under the hammer. (That is what happened when an M&P was dropped by a sailor in WWII; the gun went off, killing the man. S&W (Bill Gunn himself) redesigned the hammer block to the system used today, which is positive.)

Jim

**Unclenick** · December 16, 2008, 11:12 PM

Interesting bit of history. Thanks.

James K · December 18, 2008, 12:13 PM

BTW, that gun is Brazilian, not Bolivian. In 1937, Brazil contracted with S&W for 25,000 revolvers for (IIRC) their Naval Academy. S&W used surplus parts and even bought some spare parts, including frames, back from the U.S. government to fill the contract, with the result that the Brazilian guns have U.S. "eagle head" inspectors markings on them in addition to the Brazilian seal.

About 14,000 of those guns were brought back a few years ago. If in good condition, they are interesting collectors items.

Jim

lfmayor · December 20, 2008, 04:18 PM

Again, thank you all, esp. you Jim for the sorting out of terminology! I'll take a closer look at Numrich and their schematic.

James K · December 20, 2008, 08:52 PM

You won't find that hammer block in the schematics for the newer guns. It is shown in the parts for the M1917 (page 864 in my old catalog) as "N-53". If you look at the sideplate (N-22A) you see the slot it fits into just back of the cutout for the hand.

It is not necessary for proper functioning of the gun, but its absence could result in an accidental discharge if the gun were dropped on the hammer and the hammer pin broke.

Meantime, you still seem to have a problem with proper tension on the hand. Have you figured out yet what that problem is?

Jim

December 14, 2008, 01:53 AM	#1
lfmayor Member Join Date: January 28, 2006 Location: in the red area of a blue state Posts: 73	Looking for S&W 1917 .45acp hand torsion spring Does anyone have a hand torsion spring for sale? I have a model 1917 .45 acp Smith and Wesson DA that I had apart to duracoat and I managed to wreck the hand torsion lever spring while removing it. My pistol is an early model without the hammer block safety. This is a flat spring that rests in a slot cut on the inner side of the sideplate, in operation it provides positioning force on the hand as it reciprocates (as the hand indexes the cylinder). I'm having a bear of a time finding one, been to Brownell's, Numrich, Sarco and can't locate one. Thank you, Rich

December 14, 2008, 01:26 PM	#2
Unclenick Staff Join Date: March 4, 2005 Location: Ohio Posts: 21,732	I don't know of a source off-hand, but perhaps S&W would either have one or could refer you to some folks who might? A S&W collectors association is another possible source. The last resort is to make one. If you have the mangled one and any pieces that may have snapped off to measure, that can be done. Flat spring stock is available at Brownells. The limitation is that it is all 1/16" or 1/8" thick. Enco sells it between 2 thousandths and 1/32" thick. Borwnells also sells an AGI book on making flat springs. I suppose that is being resorted to more frequently these days. Dremel cutoff wheels will do the carving, but spray a little water or oil on first to keep the heat down. __________________ Gunsite Orange Hat Family Member CMP Certified GSM Master Instructor NRA Certified Rifle Instructor NRA Benefactor Member and Golden Eagle

December 14, 2008, 05:57 PM	#4
lfmayor Member Join Date: January 28, 2006 Location: in the red area of a blue state Posts: 73	thanks for the leads guys I appreciate the help folks... never even crossed my mind to talk to a collectors group, I'll search some up online. Sal... yes, everything still works, except that I have to manually index the cylinder. This was an old Bolivian (I think) that had the fancy unit and government marks, the finish was in real bad shape. I liked the way it shot, the bore didn't look all that great but it hits where you point it. When the mainspring failed and while I had it apart I decided to Duracoat it. It looks great now, in woodland tan, except for the manual indexing . UncleNick... I'll try and build one out of last recourse, this spring has some "funny" shapes in it and it might be a real bear to try to duplicate, it looks like a ton of hand filing. Do you just heat to a cherry red and oil quench to make a spring? I'll get her right again, the pistol just has a good feel to it, pointability I'll call it.

December 14, 2008, 08:55 PM	#6
Bill DeShivs Senior Member Join Date: April 7, 2006 Posts: 11,101	Heating spring steel to red and quenching HARDENS the metal. You must then polish and TEMPER the spring by heating it to just past blue. Let it air cool. If the spring is small, you can temper in a toaster oven at 450-500 degrees. __________________ Bill DeShivs, Master Cutler www.billdeshivs.com

December 14, 2008, 09:40 PM	#7
Unclenick Staff Join Date: March 4, 2005 Location: Ohio Posts: 21,732	The basic process for 1075 spring steel is to heat it cherry red and quench it in oil, which renders it "dead hard", then to reheat it to draw it back (tempering). 500°F is one temperature that is used for this. It leaves the steel springy, but a bit brittle. Another temperature drawing range is 750°F. This leaves the spring slightly maleable, so you can bend it a bit, though it is more prone to taking a set than the lower tempered spring. Under no circumstance use a temperature between 500°F and 700°F to draw the spring. That is the temper embrittlement range for common carbon steels. If drawn back within that range, the steel not only loses tensile strength, as normally occurs as the drawing temperature is increased, but at the same time it actually becomes more brittle than it was at 500°F. By about 700°F the ductility has returned to what it was at 500°F, and tempering at higher temperatures from that point upward continues the decrease in tensile strength and increase in ductility. Note this only applies to conventional carbon steels. Other alloys can have different temper embrittlement ranges. 416 barrel steel, for example, has a temper embrittlement range that is something like 700°F to 1100°F, IIRC. The old fashioned method was to quench the spring in motor oil, then hold the oily piece in tongs while you set it on fire. The oil fire would bring it up to the lower temper range. The problem is that while that works OK on a heavier flat spring like a mainspring for a flintlock, it can overheat a thin spring. The rolled flat spring stock at Enco will already be heat treated for cut and paste spring making. You cut it and form it, like music wire. It is the higher temper (temper comes from the same root as temperature, so "high" temper means softer and more ductile and "low" temper means harder and more brittle). Here is a link to some spring tempering information. __________________ Gunsite Orange Hat Family Member CMP Certified GSM Master Instructor NRA Certified Rifle Instructor NRA Benefactor Member and Golden Eagle

December 14, 2008, 03:07 PM	#3
salvadore Junior member Join Date: January 1, 2007 Location: Idaho Posts: 2,282	Mine broke years ago, never knew what it was until now. Does your gun still work?

December 14, 2008, 07:27 PM	#5
salvadore Junior member Join Date: January 1, 2007 Location: Idaho Posts: 2,282	The reason I asked is because my brazilian surplus 1917 still works just fine. It is the most accurate shooter I own.

December 14, 2008, 11:34 PM	#8
James K Member In Memoriam Join Date: March 17, 1999 Posts: 24,383	Hi, lfmayor, All good advice, but unfortunately all based on an erroneous idea. The hand spring in a 1917 is a coil spring that sits in a hole in the front of the trigger and operates the hand through a pivoting lever that is pinned into the top of the trigger. If the hand does not have tension the hand lever may be missing, bent or not engaged, the hand lever spring may be missing or damaged, or the small pin in the hand may be broken or bent. But the spring in the sideplate has nothing to do with it. Now to that spring in the sideplate. That is an early version of a hammer block. It is its own spring and is designed to be pushed back into the sideplate by the cam surface on the hand. That way, the firing pin cannot reach the cartridge unless the trigger is pulled. But if the spring breaks or fails, the hammer block won't work and a hard enough blow on the hammer will set off a round under the hammer. (That is what happened when an M&P was dropped by a sailor in WWII; the gun went off, killing the man. S&W (Bill Gunn himself) redesigned the hammer block to the system used today, which is positive.) Jim

December 16, 2008, 11:12 PM	#9
Unclenick Staff Join Date: March 4, 2005 Location: Ohio Posts: 21,732	Interesting bit of history. Thanks. __________________ Gunsite Orange Hat Family Member CMP Certified GSM Master Instructor NRA Certified Rifle Instructor NRA Benefactor Member and Golden Eagle

December 18, 2008, 12:13 PM	#10
James K Member In Memoriam Join Date: March 17, 1999 Posts: 24,383	BTW, that gun is Brazilian, not Bolivian. In 1937, Brazil contracted with S&W for 25,000 revolvers for (IIRC) their Naval Academy. S&W used surplus parts and even bought some spare parts, including frames, back from the U.S. government to fill the contract, with the result that the Brazilian guns have U.S. "eagle head" inspectors markings on them in addition to the Brazilian seal. About 14,000 of those guns were brought back a few years ago. If in good condition, they are interesting collectors items. Jim

December 20, 2008, 04:18 PM	#11
lfmayor Member Join Date: January 28, 2006 Location: in the red area of a blue state Posts: 73	Barking up the wrong tree Again, thank you all, esp. you Jim for the sorting out of terminology! I'll take a closer look at Numrich and their schematic.

December 20, 2008, 08:52 PM	#12
James K Member In Memoriam Join Date: March 17, 1999 Posts: 24,383	You won't find that hammer block in the schematics for the newer guns. It is shown in the parts for the M1917 (page 864 in my old catalog) as "N-53". If you look at the sideplate (N-22A) you see the slot it fits into just back of the cutout for the hand. It is not necessary for proper functioning of the gun, but its absence could result in an accidental discharge if the gun were dropped on the hammer and the hammer pin broke. Meantime, you still seem to have a problem with proper tension on the hand. Have you figured out yet what that problem is? Jim