In late 2007 Magpul Industries Corp developed the Masada Concept Rifle that featured a polymer hand guard with three elongated vent holes that acted as a negative mounting surface for accessory rails.
These slots became one of the first “negative space” attachment systems that allowed the user to put mounting rails only where they were needed, as opposed to covering the entire surface with mounting rails, which are then covered with panels. The system also
allowed direct mounting of accessories, such as fore-grips and flashlights, with no rail interface needed.
In 2009 the MOE hand guards for the common AR15/M16 firearms were released, bringing the same slot system, along with rails, flash light mounts, grips and other accessories to the mainstream.
In the years since the MOE slot system has been released, several million MOE slot compatible accessories have been produced. Initially introduced as a Magpul-specific system, several other companies have built MOE slot compatible accessories in the years
since its release.
The MOE system was never officially released as an open standard, and the requirement to have access to the back side of the mounting surface limited its application.
Additionally, depending on the accessory item, the spacing increments were not always small or uniform enough for desired placement. These characteristics made MOE slots and accessories less ideal to use with free-float hand guards, which did not allow
back side access to the mounting surface. Rather than documenting and publishing the existing MOE slot information and weld nut system, Magpul engineers used this opportunity to substantially improve the feature set of the MOE system. The result is the M-LOK.
M-LOK stands for Modular Lock system. The M-LOK system retains an elongated slot appearance, similar to MOE slots (with different dimensions). The new slot is larger, has squared sides, and the new system adds the following feature set: M-LOK
• DIRECT MOUNT CAPABILITY
• CAMMED T-NUT
• OPTIMIZED FOR METAL AND POLYMER MANUFACTURING
• RECOIL/IMPACT MITIGATION LUGS
• INTERMEDIATE SPACING OPTION
• MULTI-DIRECTIONAL MOUNTING
• BACKWARDS MOE COMPATIBILITY
DIRECT MOUNT CAPABILITY
Accessories are mountable directly from the front face of the slot. No access from the rear of the system is needed.
The M-LOK direct attachment system features a custom, cammed T-Nut that positions the T-Nut consistently for installation and removal. Simply adjust the gap between the T-Nut and accessory to match the thickness of the mounting surface, align the T-Nuts
with the slot, and insert in the desired location. An initial ¼ to ½ turn of the screw for each T-Nut rotates the nut into engagement and then you may tighten normally.
OPTIMIZED FOR METAL AND POLYMER MANUFACTURING
Simple, rounded, rectangular slots with no sharp edges, complex geometry, or undercuts make the M-LOK slots optimal for high volume metal and polymer manufacturing
The M-LOK slots require no special cutters or angle gauges in the manufacturing process. With injection molding, the lack of an undercut allows simple mold design. All of this results in the lowest manufacturing costs possible.
RECOIL/IMPACT MITIGATION LUGS
Accessories feature recoil mitigation lugs with full recoil lug support in all 4 axes of movement, preventing movement of the system under recoil or rough handling, allowing repeatable accuracy in removal and reinstallation.
INTERMEDIATE SPACING OPTION
M-LOK accessories can be direct mounted entirely within a slot or bridging between/across slots, making the adjustment interval smaller than the size of a single slot. (Intervals equal two Picatinny rail slots (20mm) of adjustment). Full, 4 axis recoil lug support is maintained at every interval.
Accessories can be mounted facing toward the front or the rear (180 degrees difference), with full recoil lug support—the system does not need to be oriented in a specific direction to function properly.
BACKWARDS MOE COMPATIBILITY
In addition to the soon-to-be released, dedicated M-LOK accessory line, current MOE accessories will work with the M-LOK slots via an adapter plate, giving the M-LOK system access to millions of accessories already fielded for the MOE system.