Forward Controls Design JCW Joint Castle Nut Wrench



Product Description

JCW (Joint Castle nut Wrench) is a dedicated, heavy-duty twin castle nut wrench, precision CNC machined from 4140 steel, heat-treated, and has a black oxide finish.

Like many AR users, FCD used either a heavy and unwieldy armorer’s wrench, or a cheap stamped sheet metal castle nut wench that couldn’t be used with a torque wrench, both work, but neither is great. One is overkill, the other is barely adequate.

The handy JCW combines two castle nut wrenches in one. On one end, it has a conventional 3 lug castle nut wrench, spanning 180 degrees. On the other end, it has a unique two-lugs wrench, spaced only 90 degrees apart. JCW measures 3.5″x 1.84″ (at its widest), but is surprisingly heavy at 3.14oz, due to its 4140 steel construction. JCW was designed from the start to be used with a torque wrench.

On some end plates with QD swivel sockets, the sockets housing masks a good portion of the castle nut’s circumference, and there are occasions where not all 3 wrench notches are accessible. FCD’s own ESF (End plate, Sling adapter, Forward Controls) covers up 1/4 of the castle nut’s circumference (ESF’s QD swivel housing acts as a backdrop to ensure it won’t bend under unforeseen pulling force) JCW’s 2 lug wrench is designed specifically for this task.

JCW has a center socket for use with a torque wrench (1/2″ drive). TM calls for 38 to 42 ft/Lb of torque to be applied to the castle nut prior to staking in two places, this torque value is conveniently engraved on the JCW as well.

JCW is proudly designed and made in the US, it is a collaboration between Forward Controls Design and Arson Machine Co, OR.

Torque value is 38 to 42 ft-lb, with no adjustment needed for the 1″ of length between the center of the 1/2 drive and the lugs.




Technical Information


Black Oxide



Catalog Location

California Prop 65 Warning

WARNING: This product can expose you to chemicals, which are known to the State of California to cause Cancer and Reproductive Harm. For more information visit

Customer Reviews

Based on 3 reviews
Brendan G.
Duck, duck…..

Must have tool for the pro or the weekend warrior, throw away that milspec tool after you pick this one up. Game changer

Alexander S.

Just the tool I was looking for my at build

C. A.
You know what it is

If you know what FCD is about then you already know.

If you don't know, or are just hunting for a castle nut wrench, then this is probably one of, if not the best, dedicated castle nut wrenches. Can't recommend highly enough.