The sustain block is the brass mass that hangs below the base plate and transfers string vibration into the body. When the original block cracks, strips its string saddle threads, or simply needs replacing, this is the part that goes back in. The FR1TB37 is a nickel-plated brass block made for the Floyd Rose 1000 Series tremolo system.

Before ordering, measure your body cavity and your existing block. The block length has to clear the routed cavity — too long and the block bottoms out before a full dive; too short and the springs sit at the wrong angle and the bridge won't return to pitch. The mounting screw pattern also has to match your base plate exactly. There is no workaround for either of these constraints. If you are pulling a block from a different series or a licensed copy, check the screw spacing against your plate before assuming it will drop in.

The block material here is nickel-plated brass. Brass is denser than the pot-metal or zinc alloy used in some replacement blocks, which affects attack character and sustain. That is a playing consideration, not a fit one — it does not change whether the block physically clears your cavity or bolts to your plate.

If you are not certain this is the right block for your guitar, send us the make, model and year and we will tell you whether it fits.