1/4" UNC - 20tpi; 7/16" across flats of head; 3/4" thread length.
5/16" UNC - 18tpi; 1/2" across flats of head; 7/8" thread length.
3/8" UNC - 16tpi; 9/16" across flats of head; 1" thread length.
7/16" UNC - 14tpi; 5/8" across flats of head; 1.1/8" thread length.
1/2" UNC - 13tpi; 3/4" across flats of head; 1.1/4" thread length.
All bolts are partly threaded.
Thread lengths stated are approximate and may vary between batches.
Bright zinc plated.
Manufactured to BS1768.
Bolt lengths do not include the head.