“Just stumbled upon your website, after beginning a search to start a long-held desire to build an instrument, and all I can say is, "WOW'!!!! What an absolute treasure trove of delights, information, goodies! I look forward to ordering the fruits of a trawl through your extensive, if not mind-blowing array of products! WOW!"

David X

Truss Rod, double action welded nut

Longer keystock facilitates easy nut adjustment.
TREDN/TRSDN can be adjusted 3 ways: hex key, standard head screwdiver, or a 1/4 inch hex driver.

Protected by U.S. Patent No. 6,259,008, this is the best rod on the market these days. Combining the best of several designs, this rod offers adjustment capabilities as well as several other advantages over rods of similar design. This rod requires a 3/8" deep x 1/4" wide slot. As the square stock bears against the bottom of the fingerboard, no filler strip is necessary. Turn the nut one way and the rod turns one way, turn the nut the other way, the rod turns the other way! With this rod the nut is actually welded onto the adjusting rod which has been right-hand threaded on one end, and reverse threaded the other. The bottom, round rod is covered with heat-shrink tubing like our compression rod, to protect against rod buzz. This rod requires a slot 1/4" wide x 3/8" deep. The bar-stock dimensions and the round-stock OD with the heat-shrink tubing is the same and makes for easy installation. This rod goes with all of pre-carved necks (see neck woods).

Our newest rods TRSDN and TREDN are an improvement on the TRSD and TRED rods in that they have 3 ways the nut can be adjusted. Should the hex key-way ever strip, they can also be adjusted with a standard head screwdriver or a 1/4" hex driver.

Please Note: With the exception of the TRMR made in Japan, all of the truss rods we carry are made, inspected and tested in the USA. Still, we urge you to carefully inspect each rod you receive to make sure it meets your specifications. Once installed, a truss rod can be extremely difficult to replace or repair. Put each rod in a vise and turn the nut beyond its normal range of adjustment (turn it both ways if it is a two-way rod). As with all of our products, LMI is not responsible for any effect of a defective truss rod, or any related costs, beyond the price of the truss rod itself. In keeping with our return policy, we are happy to replace or refund the cost of any rod that you are not happy with. Please call for a return authorization number within 2 weeks of receiving your order. Modification of the rod in any way voids your warranty.

Luthier Robert O’Brien: 
Truss rods and how to install
LMI double action rods.

 *Allen wrenches are not included with truss rod.


Note: Overall length is the length of rod + nut.

SKU Product Name In Stock Each 3+  
TRSDS Truss rod, 12" x 3/8" (overall length 13")
Yes $27.93 $24.83
TRSDA Truss rod, 13 1/4" x 3/8" (overall length 14 1/4")
Yes $27.93 $24.83
TRSD Truss rod, steel string, 14 1/2" x 3/8" (overall length 15 1/2")
Yes $27.93 $24.83
TRSDN Truss rod, steel string, 14 1/2" x 3/8" (overall length 15 1/2")
Yes $28.93 $25.75
TRED Truss rod, electrics, 17"x 3/8" (overall length 18")
Yes $27.93 $24.83
TREDN Truss rod, electrics, 17"x 3/8" (overall length 18")
Yes $28.93 $25.75
TRBSD Truss rod, bass, 22 3/4" x 3/8" (overall length 23 3/4")
Yes $27.93 $24.83
TRW 9/64" Allen wrench for LMI truss rod Yes $1.47 $1.31