A: Sorry I don’t have one available to measure, but I can tell you it is definitely not a “deep socket” .
A: Hi, there isn't a true equivalent to the 18 mm socket. That size socket would fall between a 11/16 in and 3/4 in. SAE socket.
A: Yes we do have both of these sockets available. The 21mm is (Model # H2D12P21M Internet #202934324 Store SKU #677616) and the 13/16 is (Model # H2D12P1316 Internet #202934267 Store SKU #631822)
|Name||1/2 in. Drive 3/4 in. 12-Point SAE Standard Socket||1/2 in. Drive 13/16 in. 12-Point SAE Standard Socket||1/2 in. Drive 15/16 in. 12-Point SAE Standard Socket||1/2 in. Drive 1/2 in. 12-Point SAE Deep Socket|
|Socket Size||3/4 in||13/16 in||15/16 in||1/2 in|
|Drive Size||1/2 in||1/2 in||1/2 in||1/2 in|
|Number of Pieces||1||1||1||1|
|View Product||View Product||View Product||View Product|