This is from the beretta USA FAQ

The front sight threads measure 2.5 x .45 mm.

The mid bead threads measure 2.2 x .45mm

Both styles are right hand threaded.

i believe the 2.5 x .45 mm. thread is the same as a 3-56. the 2.2 x .45 is the same as a 2-56.

On the other hand I bought a 2.2 x .45 to replace a mid-bead on a 682 gold - and it didn't fit. It could be that it had been tapped out in years gone by.

John

 

The thread for the front size is NOT 3-56. It's close, but 3-56 will loosen on you. Use the proper size.

 

Thanks. I was told the 3-56 could be used in place of the 2.5x.45 but it might be a little loose. My thought is I can't find a 2.5 and get a 3-56; could loctite (the brand that can be loosened if needed), be applied to the threads to sufficiently tighten the 3-56? I have been looking on Midway's website and it appears the 3-56 is a common size and they have the white beads that I am looking for. Also, they list the 3-56 together with the 2.5x.45; so it appears either size could be used. However, they don't list any such size as a 2.2x.45 or a 2-56 for the middle bead. What I an trying to do is install 2 ivory colored beads on my over/under barrels. Thanks again. Ed

 

I did exactly what you're talking about. Because the 3-56 is a smaller size the threads on the bead didn't fully seat in the tapped hole in the barrel. When I tightened it, the threads in the barrel stripped. I had to permanently glue it in with JB Weld.

 

dickgtax: Sorry for the confusion. I was trying to edit my last response when you inserted your input. Like I stated, Midway list a ton of front sights and even include the 2.5x.45 measurement with the 3-56 measurements on the same sights.

 

You folks are comparing 2.5 x .45 and 3-56 threads like they are the same thing. 2.5 is a metric thread. The proper designation would be M 2.5, or M6. You are comparing apples to oranges my friends. The numbers don't even refer to the same things. .45 refers to thread width while 56 refers to tpi. (threads per inch) Why would you want to loctite the wrong sight into your gun?

Ed

 

I just wish I could find an outlet where I could obtain the proper sized sight.

 

Tru-glo and Hi-Viz show them as different sights, and not interchangable. Why would they do that if they were the same?

 

Try: Coles Gunsmithing, Brownells, 100 Straight Products.

 

Well according to Hi-Viz the 3-56 fits the Beretta. Now I need to find an ivory sight to fit not only the front sight but the middle sight. Still haven't figured out the true size of that one.

 

http://www.truglosights.com/images/Gun%20Chart.pdf
*Supreme and Super X2 barrels produced in 2003 or later have M3x0.5mm threads. Please note that manufacturers may periodically change specifications.
We suggest contacting the manufacturer directly regarding specifications before ordering.
UNIVERSAL SIGHTS Turkey / Muzzleloader Sights Wing Sights Bead Replacement Sights BEAD THREAD
Ribbed shotgun barrels TG94, TG94D, TG950, TG950G, TG950X, TG950XD, TG960 TG90, TG90D, TG90X, TG91, TG103U TG947U, TG948U, TG948UD, TG949, TG949D
Plain shotgun barrels — 12 or 20 ga. TG92A, TG93A, TG92HA, TG93HA
Plain shotgun barrels — 410 ga. TG92B, TG93B
Muzzleloaders TG131ML, TG958, TG958G, TG958X
The above ”Universal Sights“ can be used in addition to any manufacturer specific sight listed below.
BERETTA Turkey/Slug Sights Wing Sights Bead Rep lacement Sights Bead Thread
AL390, AL391 Urika, A391 Xtrema TG941XC, TG944C, TG946C, TG962C TG905X, TG957C TG947C, TG948C, TG954D M2.6x0.45
Competition Models TG947C, TG948C, TG954D M2.6x0.45
BENELLI Turkey/Slug Sights Wing Sights Bead Rep lacement Sights Bead Thread
Super Black Eagle, M1 Field, TG941XD, TG944D, TG946D, TG962D TG904X, TG957D TG947C, TG948C, TG954D M2.6x0.45
Montefeltro, Legacy — 12 ga.
Nova — 12 ga. TG941XD, TG944D, TG962D, NO TRU•POINT SIGHTS TG904X, NO TRU•POINT SIGHTS TG947C, TG948C, TG954D M2.6x0.45
Legacy, Montefeltro, Nova — 20 ga. TG941XC, TG944C, TG946C, TG962C TG905X, TG957C TG947C, TG948C, TG954D M2.6x0.45
BROWNING Turkey/Slug Sights Wing Sights Bead Rep lacement Sights Bead Thread
Gold Series, A5 TG941XC, TG944C, TG962C, NO TRU•POINT SIGHTS TG905X TG947E, TG948E, TG954E M3x0.5
BPS, Gold Light 10 TG941XD, TG944D, TG962D, NO TRU•POINT SIGHTS TG904X TG947E, TG948E, TG954E M3x0.5
Citori, Cynergy, BT-99 Vent ribs vary among 3/16" - 7/16" Vent ribs vary among 3/16" - 7/16" TG947E, TG948E, TG954E M3x0.5*
Maxus, Silver TG941XA, TG942XA, TG943XA, TG944A, TG945, TG946A, TG901X, TG902X, TG103 TG947E, TG948E, TG954E M3X0.5
TG962A, NO TRU•POINT SIGHTS
*M1200, Superposed & older Citori’s have 3-56 threads.
CHA RLES DALY Turkey/Slug Sights Wing Sights Bead Rep lacement Sights Bead Thread
All Shotguns TG945, TG941XA, TG942XA, TG943XA, TG944A, TG962A TG901X, TG902X, TG103 TG947E, TG948E, TG954E M3x0.5
FRANCHI Turkey/Slug Sights Wing Sights Bead Rep lacement Sights Bead Thread
Field Models TG941XC, TG944C, TG962C, NO TRU•POINT SIGHTS TG905X, NO TRU•POINT SIGHTS TG947E, TG948E, TG954E M3x0.5
HA STINGS BARRELS Bead Rep lacement Sights Bead Thread
All Shotgun Barrels TG947B, TG948B, TG954B 3-56
HENRY Turkey/Slug Sights
Golden Boy .22 LR TG112
Golden Boy .22 MAG/17HMR, Big Boy 45 Colt TG114
ITHA CA Turkey/Slug Sights Wing Sights Bead Rep lacement Sights Bead Thread
Model 37 Deerslayer/Turkeyslayer TG961D
Model 37 (with 5/16" vented rib) TG941XD, TG944D, TG962D, NO TRU•POINT SIGHTS TG904X, NO TRU•POINT SIGHTS TG947A, TG948A, TG954A
All Shotguns TG947A, TG948A, TG954A 6-48
KRIEGHO FF Bead Rep lacement Sights Bead Thread
All Shotguns TG947B, TG948B, TG954B 3-56
MARLIN Turkey/Slug Sights
Model 336 with front ramp TG114
Lever Action Guide Rifles with front ramp TG112
MOSSBERG Turkey/Slug Sights Wing Sights Bead Rep lacement Sights Bead Thread
500 Plain Barrel Shotgun TG92A, TG93A TG947D, TG948D, TG954C
500, 835, 9200 Shotgun TG941XB, TG942XB, TG943XB, TG944B, TG9453, TG946B, TG962B TG957B, TG911X, TG912X, TG1033 TG947D, TG948D, TG954C 5-40
Reserve Series O/U TG947E, TG948E, TG954E M3x0.5
695 Slug Gun TG961M
NEW ENGLAND/H&R FIREARMS Turkey/Slug Sights Wing Sights Bead Thread
12 ga. Turkey Guns TG92A, TG93A, TG92HA, TG93HA
410 ga. Models TG92B, TG93B
Topper, Pardner, Excell TG941XD, TG944D, TG946D, TG962D, NO TRU•POINT SIGHTS TG904X, TG945
PERAZZI Bead Rep lacement Sights Bead Thread
All Shotguns TG947C, TG948C, TG954D M2.6x0.45
REMING TON Turkey/Slug/Muzzleloader Sights Wing Sights Bead Rep lacement Sights Bead Thread
870, 1100, 1187 TG941XA, TG942XA, TG943XA, TG944A, TG945, TG946A*, TG962A TG957A*, TG901X, TG902X, TG103 TG947A, TG948A, TG954A
SP-10 TG941XB, TG942XB, TG943XB, TG944B, TG9453, TG962B TG911X, TG912X, TG1033 TG947A, TG948A, TG954A
Shotgun Slug Barrels TG961R, TG110W**
700 ADL, BDL, 7400, 7600 Rifles TG961R, TG110W**
700 Series Muzzleloaders TG110W
All Shotguns TG947A, TG948A, TG954A 6-48***
*Excluding 2007 or later 870 Express.
**Only fits two-piece front sights.
***All 870 Express barrels and some 870. 1100 & 1187 barrels have pressed beads, which can easily be tapped by a gunsmith.
RUGER Turkey/Slug Sights Wing Sights Bead Rep lacement Sights Bead Thread
Red Label Shotguns TG941XD, TG944D, TG962D TG957E, TG904X TG947B, TG948B, TG954F, TG954B
All Shotguns TG947B, TG948B, TG954F, TG954B 3-56
10/22 Rifle TG111W
SAVAGE Turkey/Slug Sights Wing Sights
All Shotguns TG941XD, TG944D, TG962D, NO TRU•POINT SIGHTS TG904X, NO TRU•POINT SIGHTS
SKB Bead Rep lacement Sights Bead Thread
All Shotguns TG947A, TG948A, TG954A 6-48
STOEGER Turkey/Slug Sights Wing Sights Bead Rep lacement Sights Bead Thread
Model 2000, P-350 Pump (all models) TG941XD, TG944D, TG962D, NO TRU•POINT SIGHTS TG904X, NO TRU•POINT SIGHTS TG947C, TG948C, TG954D M2.6x0.45
Condor Supreme, Uplander, Coach Gun & TG947D, TG948D, TG954C 5-40
Double Defense
TRADITIONS Turkey/Slug/Muzzleloader Sights Wing Sights
Turkey II, Waterfowl II, ALS 2100 Field TG945, TG941XA, TG942XA, TG943XA, TG944A, TG962A TG901X, TG902X, TG103
VERONA Turkey/Slug Sights Wing Sights Bead Thread
All Shotguns TG945, TG941XA, TG942XA, TG943XA, TG944A, TG962A TG901X, TG902X, TG103 Pressed Bead
WEATHERBY Turkey/Slug Sights Wing Sights Bead Rep lacement Sights Bead Thread
Orion (mfg by SKB) TG941XB, TG942XB, TG943XB, TG944B, TG9453, TG962B TG911X, TG912X, TG1033 TG947A, TG948A, TG954A 6-48
SA-08, PA-08 — 12 ga. TG941XD, TG944D, TG962D, NO TRU-POINT SIGHTS TG904X TG947E, TG948E, TG954E M3x0.5
Orion/Athena S/S — 12/20 ga. (tapered) TG947E, TG948E, TG954E M3x0.5
Orion/Athena O/U — 12 ga., SA-08 — 20 ga. TG941XA, TG942XA, TG944A, TG962A, NO TRU-POINT SIGHTS TG901X, TG902X, TG103 TG947E, TG948E, TG954E M3x0.5
Orion/Athena O/U — 20 ga. TG941XC, TG944C, TG962C, NO TRU-POINT SIGHTS TG905X TG947E, TG948E, TG954E M3x0.5
WINCHESTER Turkey/Slug Sights Wing Sights Bead Rep lacement Sights Bead Thread
1200, 1300, 1400, Super X2 Shotguns TG941XB, TG942XB, TG943XB, TG944B, TG9453, TG946B, TG962B TG957B, TG911X, TG912X, TG1033 TG947B, TG948B, TG954B 3-56*
Super X3 Shotguns TG941XC, TG944C, TG962C TG905X TG947E, TG948E, TG954E M3x0.5
1300

 

I've been using 3-56's on Berettas, front and middle, for about 20 years without problems.

 

.45 in metric designation is the thread pitch - as in 0.45 mm / thread. There are 25.4 mm per inch. so converting the .45 to US ANSI thread designation is 25.4/0.45 = 56.44 threads per inch. The major diameter of 2.5 mm = 2.5/25.4 =0.0984" , the specs for a #3 screw major diameter range from a min of 0.0949 to 0.099" probably should check pitch diameters and tolerances - but i think a 3-56 and an m2.5 x .45 are very, very close.

pitch M2.5 = 2.117-2.188 or 0.0833" - 0.0861" ANSI pitch specs for a # 3 (2A) are 0.0845 - 0.0867 IOW very -very close. It would take a thread on the extreme edge of tolerance to not meet specs of either metric or US ANSI specs.

FWIW.

john

 

Mike & John: Thanks a lot. I just could not figure out exactly what I needed. I had a feeling that the 3-56 would work on the front sight; but I was totally unsure as to what the thread was for the middle bead. Thanks again. Ed

 

I have the metric replacements you are looking for.

Whiz