Arisaka Defense 40-Degree M-Lok Aluminum Adapter - Black Finish

The Arisaka Defense 40-Degree M-Lok Aluminum Adapter opens up weapon mounting options on AR handguards and rails where standard M-Lok slots fall short. If your rail system lacks M-Lok slots at the 1:30 and 10:30 positions—or you need to angle an accessory away from your primary sighting system—this adapter fills that gap with three half-height M-Lok slots offset at 40 degrees. It's a small, smart solution for shooters who want flexible placement without changing their entire setup.

Built from 6061-T651 aluminum and hard coat anodized per MIL-A-8625 Type III spec, this adapter is rugged enough for duty rifles and competition guns alike. At just 0.6 ounces and 2.2 inches long, it adds negligible weight while giving you the real estate to mount a tactical light button to the side of your handguard for thumb activation, mount a vertical grip at an angle to clear drum magazines, or configure your accessories exactly as your gun demands. Installation is straightforward with the included M-Lok nuts and Torx screws—you'll need an IP20/T20 Torx driver and medium-strength threadlocker, torqued to 30 inch-pounds.

Arisaka Defense engineered this adapter for shooters who refuse to compromise on ergonomics or modularity. Whether you're tuning a duty carbine, competition rifle, or precision build, this aluminum block lets you reclaim control of your handguard real estate and place gear exactly where it works best for your grip and trigger hand.

Key Features

• Three half-height M-Lok slots at 40-degree offset for side-mounted accessories
• Precisely machined from aircraft-grade 6061-T6 aluminum
• MIL-A-8625 Type III hard coat anodized for corrosion resistance and durability
• Minimal weight (0.6 oz) and compact footprint (2.2 in) won't affect handling or balance
• Ideal for mounting light buttons, vertical grips, or other M-Lok accessories at non-standard angles
• Made in the USA

Specifications

Brand	Arisaka Defense
Product Type	M-Lok Adapter
Material	6061-T651 Aluminum
Finish	MIL-A-8625 Type III Hard Coat Anodized (Black)
Offset Angle	40 degrees
M-Lok Slots	Three half-height slots
Length	2.2 inches
Weight	0.6 ounces
Hardware Included	Two M-Lok nuts, two 10-24×5/16" Torx button head screws
Torque Specification	30 inch-pounds (with medium-strength threadlocker)
Tool Required	IP20/T20 Torx driver (not included)
Made	USA

Frequently Asked Questions

What handguards and rails are compatible with this M-Lok adapter?

This adapter works on any rail or handguard with M-Lok slot mounting. It's especially useful on systems that lack M-Lok positions at the 1:30 and 10:30 clock positions, or on the 6 o'clock slot if you want to angle a vertical grip outboard.

Can I mount a light button or vertical grip with this adapter?

Yes. The adapter's three half-height M-Lok slots accept standard M-Lok accessories. Common applications include mounting a Unity Hot Button for thumb activation of a weapon light, or combining it with a vertical grip on the bottom rail to angle the grip away from your grip area and provide clearance around larger magazines.

What's included, and what tools do I need to install it?

The adapter comes with two M-Lok nuts and two 10-24×5/16" Torx button head screws. You'll need an IP20/T20 Torx driver and medium-strength threadlocker. Torque the screws to 30 inch-pounds. The Torx driver is not included.

How much weight does this add to my rifle?

At 0.6 ounces, the adapter is negligible in terms of weight—you won't notice it on your rifle's overall balance or handling.