BT Transition Couplers

BT Transition couplers are designed to connect reinforcing bars of different diameters whilst still maintaining the full tensile strength of both reinforcing bars, ensuring the failure mode is ductile failure of the smaller bar.

For Type A transition connections, both bars utilise standard Type A BT threads with a special coupler to connect the two bars. Transition connections requiring types B or C systems use the standard BT thread for the smaller bar and a modified BT thread for the larger bar which uses a thread pitch matching the smaller thread to allow simultaneous rotation of the coupler on both bars.

Locknuts for Type C connections use the standard locknut for the smaller bar and a modified locknut with the modified thread pitch for the larger bar.

Download the technical brochure for full product details:

BT Transition Type A

Type A transition connections utilise the same Type A BT threads as the standard system with a special internally threaded coupler to connect the two different sized cold-forged and threaded bar ends together. Type A connections are used where the continuation bar can be rotated

BT Transition Type B

Type B connections utilises a longer thread on the smaller bar equal to the length of the coupler. The thread on the larger bar and the coupler is modified with a pitch matching the smaller thread. The coupler needs to be rotated from the smaller diameter rebar onto the larger. Type B connections are used where the continuation bar can be rotated for no more than one revolution.

BT Transition Type C

The Type C connection utilises the same coupler and thread pitches as for the Type B, together with two locknuts and longer threads on the bar ends. The coupler needs to be rotated from the smaller diameter rebar onto the larger. Type C connections are used where the continuation bar cannot be rotated.