We ship worldwide — Singapore, Australia, Malaysia, Indonesia, Philippines, India, Middle East & more

3G Electric
RFQ CartGet a QuoteSign inSign up
APPROVED VENDOR Key Locking Insert: Thin Wall, 4 Keys, M12x1.25 Int Thrd Sz, M16x1.5 Ext Thrd Sz - Mil. Spec. Key-Locking Inserts
APPROVED VENDORMil. Spec. Key-Locking Inserts

APPROVED VENDOR Key Locking Insert: Thin Wall, 4 Keys, M12x1.25 Int Thrd Sz, M16x1.5 Ext Thrd Sz

The APPROVED VENDOR Key Locking Insert is a thin-wall, mil. spec. insert with 4 keys, M12x1.25 internal thread size, M16x1.5 external thread size, plain finish, and coarse thread type. It meets Fed Std. H28/21 and MJ…

SKU 3G-OTH-531701

Brand
APPROVED VENDOR
Item
Key Locking Insert: Thin Wall, 4 Keys, M12x1.25 Int Thrd Sz, M16x1.5 Ext Thrd Sz
Category
Mil. Spec. Key-Locking Inserts
Available to Order
Trade pricing by quote — replies within 24h
Qty
WhatsApp an engineer
No account needed — your quote request goes straight to our engineers. A free account lets you track quotes and re-order faster.
Worldwide Shipping
Air & sea freight
Datasheet on Request
Technical specs
1-Day Quote
Replies within 24h

Technical Specifications

APPROVED VENDOR
Manufacturer Part Number
217-076556
Type
M12x1.25 Int Thrd Sz, M16x1.5 Ext Thrd Sz, Plain, 10 PK
Keys
4
Wall Type
Thin Wall
Finish Type
Plain
Thread Type
Coarse
Industry Standards
Fed Std. H28/21, MJ Form
Compatible Tap Size
M16x1.5
External Thread Fit
2A
Internal Thread Fit
3B
Material Grade/Class
18-8
System of Measurement
Metric
View Full Spec Sheet

Technical Documents

No technical documents available for this product.
Request documentation →
Not sure this is the right part? Get a recommendation.

Need installation or engineering help?

Installation, commissioning, maintenance plans, system design, and bundled product + service quotes — one team handles the full scope.
Talk to an engineer

Ask a question

APPROVED VENDOR Products
3G Electric (S) Pte. Ltd. — Singapore

Product Description

The APPROVED VENDOR Key Locking Insert is a thin-wall, mil. spec. insert with 4 keys, M12x1.25 internal thread size, M16x1.5 external thread size, plain finish, and coarse thread type. It meets Fed Std. H28/21 and MJ Form standards, with a compatible tap size of M16x1.5, external thread fit 2A, internal thread fit 3B, and is made from 18-8 material in metric measurement (MPN 217-076556, 10 PK).

Frequently Asked Questions

What is an APPROVED VENDOR key locking insert used for?

This thin-wall key locking insert with 4 keys is used to repair or reinforce tapped threads in metal assemblies, particularly in aerospace and defense applications. It meets Fed Std. H28/21 and MJ Form standards, ensuring reliable thread locking in high-vibration environments.

What are the specifications of the APPROVED VENDOR key locking insert 217-076556?

This insert has M12x1.25 internal thread size, M16x1.5 external thread size, plain finish, coarse thread type, and 18-8 material grade. It includes 4 keys, external thread fit 2A, internal thread fit 3B, and is compatible with M16x1.5 tap size. Supplied in a 10-pack.

Where to buy APPROVED VENDOR key locking inserts worldwide?

3G Electric supplies APPROVED VENDOR key locking inserts worldwide. We handle full logistics, customs clearance, and delivery to your facility. Contact us for pricing and lead time on this M12x1.25 internal thread, M16x1.5 external thread insert (MPN 217-076556).

How to install a thin-wall key locking insert?

Installation requires tapping the hole to the compatible tap size (M16x1.5), then driving the insert using a proper installation tool until it is flush or slightly below the surface. After installation, set the keys using a key-setting tool to lock the insert in place. Follow standard mil-spec practices.

Used in

Common applications for APPROVED VENDOR
Laboratory sampling — APPROVED VENDOR clear wide mouth glass bottles for collecting and storing liquid samples in non-sterile environments.
Steam heating maintenance — APPROVED VENDOR forged brass radiator valves for regulating steam flow in commercial building heating systems.
High-pressure cleaning — APPROVED VENDOR turbo spray nozzles for pressure washers used in industrial equipment cleaning up to 6,000 psi.
Cleanroom operations — APPROVED VENDOR vinyl task chairs for seating in ISO 5 classified manufacturing or assembly areas.
General sealing — APPROVED VENDOR natural rubber stoppers for closing laboratory flasks or test tubes in educational or research settings.
Tamper-evident security — APPROVED VENDOR brass lead and wire seals for securing utility meters, cargo containers, or access panels.

APPROVED VENDOR Products

3G Electric supplies APPROVED VENDOR mil. spec. key-locking inserts. We supply genuine products with in-stock availability on common SKUs, technical documentation, commissioning support, and warranty service — worldwide.

You might also need

Burners & Combustion →Pumps & Compressors →Spare Parts →All Products →

More from APPROVED VENDOR

View all APPROVED VENDOR parts →
Key Locking Insert: Heavy Wall, 4 Keys, M10x1.5 Int Thrd Sz, M16x1.5 Ext Thrd Sz, Plain, 10 PK (MPN 217-077367). Key specifications — Wall Type: Heavy Wall; Brand: APPROVED VENDOR; Compatible Tap Size: M16x1.5; External Thread Fit: 2A; Internal Thread Fit: 3B; Material Grade/Class: 18-8; Industry Standards: Fed Std. H28/21, MJ Form; System of Measurement: Metric.
APPROVED VENDOR
Key Locking Insert: Heavy Wall, 4 Keys, M10x1.5 Int Thrd Sz, M16x1.5 Ext Thrd Sz, Plain, 10 PK (MPN 217-077367). Key specifications — Wall Type: Heavy Wall; Brand: APPROVED VENDOR; Compatible Tap Size: M16x1.5; External Thread Fit: 2A; Internal Thread Fit: 3B; Material Grade/Class: 18-8; Industry Standards: Fed Std. H28/21, MJ Form; System of Measurement: Metric.
Key Locking Insert: Heavy Wall, 4 Keys, 7/8"-14 Int Thrd Sz, 1 1/4"-12 Ext Thrd Sz, Plain, 10 PK (MPN 217-076510). Key specifications — Wall Type: Heavy Wall; Brand: APPROVED VENDOR; Compatible Tap Size: 1-1/4"-12; Drill Bit Size: 1-11/64 in; External Thread Fit: 2A; Internal Thread Fit: 3B; Material Grade/Class: 18-8; Industry Standards: MS51832-204.
APPROVED VENDOR
Key Locking Insert: Heavy Wall, 4 Keys, 7/8"-14 Int Thrd Sz, 1 1/4"-12 Ext Thrd Sz, Plain, 10 PK (MPN 217-076510). Key specifications — Wall Type: Heavy Wall; Brand: APPROVED VENDOR; Compatible Tap Size: 1-1/4"-12; Drill Bit Size: 1-11/64 in; External Thread Fit: 2A; Internal Thread Fit: 3B; Material Grade/Class: 18-8; Industry Standards: MS51832-204.
Key Locking Insert: Heavy Wall, 4 Keys, M20-1.50 Int Thrd Sz, M30-2.00 Ext Thrd Sz, Plain, 10 PK (MPN 217-076573). Key specifications — Wall Type: Heavy Wall; Brand: APPROVED VENDOR; Compatible Tap Size: M30-2.00; Drill Bit Size: 28.10 mm; External Thread Fit: 2A; External Thread Size: M30-2.00; Internal Thread Fit: 3B; Material Grade/Class: 18-8.
APPROVED VENDOR
Key Locking Insert: Heavy Wall, 4 Keys, M20-1.50 Int Thrd Sz, M30-2.00 Ext Thrd Sz, Plain, 10 PK (MPN 217-076573). Key specifications — Wall Type: Heavy Wall; Brand: APPROVED VENDOR; Compatible Tap Size: M30-2.00; Drill Bit Size: 28.10 mm; External Thread Fit: 2A; External Thread Size: M30-2.00; Internal Thread Fit: 3B; Material Grade/Class: 18-8.
Key Locking Insert: Extra Heavy Wall, 4 Keys, 3/8"-24 Int Thrd Sz, 5/8"-11 Ext Thrd Sz, Plain, 10 PK (MPN 217-077536). Key specifications — Wall Type: Extra Heavy Wall; Brand: APPROVED VENDOR; Compatible Tap Size: 5/8"-11; External Thread Fit: 2A; Internal Thread Fit: 3B; Material Grade/Class: 18-8; Industry Standards: MS51832-204L; System of Measurement: Inch.
APPROVED VENDOR
Key Locking Insert: Extra Heavy Wall, 4 Keys, 3/8"-24 Int Thrd Sz, 5/8"-11 Ext Thrd Sz, Plain, 10 PK (MPN 217-077536). Key specifications — Wall Type: Extra Heavy Wall; Brand: APPROVED VENDOR; Compatible Tap Size: 5/8"-11; External Thread Fit: 2A; Internal Thread Fit: 3B; Material Grade/Class: 18-8; Industry Standards: MS51832-204L; System of Measurement: Inch.
Key Locking Insert: Thin Wall, 2 Keys, #2-56 Int Thrd Sz, #8-32 Ext Thrd Sz, Stainless Steel, 10 PK (MPN 217-076283). Key specifications — Wall Type: Thin Wall; Brand: APPROVED VENDOR; Compatible Tap Size: #8-32; External Thread Fit: 2A; Internal Thread Fit: 3B; Material Grade/Class: 18-8; Industry Standards: MS51830-101; System of Measurement: Inch.
APPROVED VENDOR
Key Locking Insert: Thin Wall, 2 Keys, #2-56 Int Thrd Sz, #8-32 Ext Thrd Sz, Stainless Steel, 10 PK (MPN 217-076283). Key specifications — Wall Type: Thin Wall; Brand: APPROVED VENDOR; Compatible Tap Size: #8-32; External Thread Fit: 2A; Internal Thread Fit: 3B; Material Grade/Class: 18-8; Industry Standards: MS51830-101; System of Measurement: Inch.
Key Locking Insert: Thin Wall, 4 Keys, M12x1.75 Int Thrd Sz, M16x1.5 Ext Thrd Sz, Plain, 10 PK (MPN 217-076356). Key specifications — Wall Type: Thin Wall; Brand: APPROVED VENDOR; Compatible Tap Size: M16x1.5; External Thread Fit: 2A; Internal Thread Fit: 3B; Material Grade/Class: 18-8; Industry Standards: Fed Std. H28/21, MJ Form; System of Measurement: Metric.
APPROVED VENDOR
Key Locking Insert: Thin Wall, 4 Keys, M12x1.75 Int Thrd Sz, M16x1.5 Ext Thrd Sz, Plain, 10 PK (MPN 217-076356). Key specifications — Wall Type: Thin Wall; Brand: APPROVED VENDOR; Compatible Tap Size: M16x1.5; External Thread Fit: 2A; Internal Thread Fit: 3B; Material Grade/Class: 18-8; Industry Standards: Fed Std. H28/21, MJ Form; System of Measurement: Metric.
Key Locking Insert: Heavy Wall, 4 Keys, 1/2"-20 Int Thrd Sz, 11/16"-11 Ext Thrd Sz, Plain, 10 PK (MPN 217-077506). Key specifications — Wall Type: Heavy Wall; Brand: APPROVED VENDOR; Compatible Tap Size: 11/16"-11; External Thread Fit: 2A; Internal Thread Fit: 3B; Material Grade/Class: 18-8; Industry Standards: MS51831-107L; System of Measurement: Inch.
APPROVED VENDOR
Key Locking Insert: Heavy Wall, 4 Keys, 1/2"-20 Int Thrd Sz, 11/16"-11 Ext Thrd Sz, Plain, 10 PK (MPN 217-077506). Key specifications — Wall Type: Heavy Wall; Brand: APPROVED VENDOR; Compatible Tap Size: 11/16"-11; External Thread Fit: 2A; Internal Thread Fit: 3B; Material Grade/Class: 18-8; Industry Standards: MS51831-107L; System of Measurement: Inch.
Key Locking Insert: Heavy Wall, 4 Keys, 5/16"-18 Int Thrd Sz, 1/2"-13 Ext Thrd Sz, Plain, 10 PK (MPN 217-076303). Key specifications — Wall Type: Heavy Wall; Brand: APPROVED VENDOR; Compatible Tap Size: 1/2"-13; External Thread Fit: 2A; Internal Thread Fit: 3B; Material Grade/Class: 18-8; Industry Standards: NAS1395C5; System of Measurement: Inch.
APPROVED VENDOR
Key Locking Insert: Heavy Wall, 4 Keys, 5/16"-18 Int Thrd Sz, 1/2"-13 Ext Thrd Sz, Plain, 10 PK (MPN 217-076303). Key specifications — Wall Type: Heavy Wall; Brand: APPROVED VENDOR; Compatible Tap Size: 1/2"-13; External Thread Fit: 2A; Internal Thread Fit: 3B; Material Grade/Class: 18-8; Industry Standards: NAS1395C5; System of Measurement: Inch.