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Questions & Answers
what is the outside diameter? Will it sit flush with a 9mm carbine barrel that has a 0.75in OD? Expert Answer

Stern Defense does not provide the outside diameter of their 1/2-36 to 1/2-28 thread adapter. I'd recommend reaching out to them directly for more information.

by Ethan, Gear Expert, August 19, 2022
Customer Reviews
Helpful Positive Review
“Stern” word of warning by Mischa, Verified Owner, October 2, 2020
I learned a lesson the hard way and now I share with you what I learned. If your buying a thread adapter it’s likely because you need to fit a 1/2x28 suppressor onto your 1/2x36 firearm. If it’s improperly threaded and the adapter does not align corr...
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18/18 found this helpful
Helpful Negative Review
9mm thread adapter by XJ, Verified Owner, September 19, 2025
Like a prior review i saw, this productvwas covered with surface rust in package. Not a good look. It also has a weird unthreaded section on the inner part of 1/2×28 thread that does not allow a flush fit thus requiring a washer which seems like a re...
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1/1 found this helpful
Most Recent Reviews
Works good. by Johnny Go, March 28, 2026
The product does what it’s intended to do. If you need to change your thread pitch, get this part.
Most Recent Reviews
Fits perfect by Bahooney, Verified Owner, March 1, 2026
I needed this adapter to attach a silencer to my PCC. The fit and finish is great, will be coming back to Optics Planet the next time I need an adapter.
Most Recent Reviews
Stern Defense comes to My Defense by RJ, Verified Owner, February 3, 2026
I found out the hard way that an Otter Creek Ti 9M can and a Colt AR-15 in 9M don’t play well together. Stern Defense to the rescue. The product is perfect in every way. Dark black, lightly oiled, straight, square, clean. Does the job. Thank you Ster...
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Most Recent Reviews
Take a chance by Dennis, Verified Owner, August 18, 2025
I should have purchased directly from them. The item arrived in the original packaging I assume but it must have been sitting on a shelf for awhile. Upon opening the packaging it was rusted. Not a good look to be putting on a new build.
1/1 found this helpful
Read All 6 Reviews

12% OFF + 2% Bucks

CARTMEClick to Copy Coupon Code
Eligible models will have a savings offer and the coupon code to use below. Add the item to your cart and enter coupon code for savings on that select model! Limited time only. Cannot be combined with other promotions or offers.
Color:
Black
Gun Model:
AR-15
Condition:
New

Code: 3JS-TDP-CDTPTA-5-36TO28-ADAPT

MPN: .5-36to28-adapt

UPC: 850001176347

List: $44.29Save 39%
$27.00

Product Info for Stern Defense 1/2-36 to 1/2-28 thread adapter Muzzle Device

Have a bunch of 1/2-28 9mm attachments?image

Use this adapter to convert from 1/2-36 threads to 1/2-28 threads.

Do not exceed 25 ft lbs when tightening muzzle devices.

Comes with a crush washer.

Specifications for Stern Defense 1/2-36 to 1/2-28 thread adapter Muzzle Device:

Manufacturer: Stern Defense
Color: Black
Gun Model: AR-15
Condition: New

Package Contents:

  • Stern Defense 1/2-36 to 1/2-28 thread adapter Muzzle Device

Stern Defense 1/2-36 to 1/2-28 thread adapter Muzzle Device Orderable Models

List of Orderable Models

  • Stern Defense 1/2-36 to 1/2-28 thread adapter Thread Protector, Black .5-36to28-adapt, Black, .5-36to28-adaptA , MPN: .5-36to28-adapt , UPC: 850001176347 , Code: 3JS-TDP-CDTPTA-5-36TO28-ADAPT

Stern Defense 1/2-36 to 1/2-28 thread adapter Muzzle Device Unavailable & Discontinued Models

List of Unorderable Models

  • USED, Stern Defense 1/2-36 to 1/2-28 thread adapter Thread Protector, Black .5-36to28-adapt, Black, .5-36to28-adaptA , MPN: .5-36to28-adapt -EDEMO , Code: 3JS-TDP-CDTPTA-5-36TO28-ADAPT-EDEMO-IN-C
  • USED Stern Defense 1/2-36 to 1/2-28 thread adapter Thread Protector, Black .5-36to28-adapt, Black, .5-36to28-adaptA, EDEMO2, Used, Condition Like New , MPN: .5-36to28-adapt -EDEMO2 , Code: 3JS-TDP-CDTPTA-5-36TO28-ADAPT-EDEMO2
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