This is an original DIN 933 spec bolt with a 14 mm head. During most Porsche 356 production, 8 mm bolts and nuts were used with 14 mm across the flats of the head (= 14 mm wrench). Total length is 15 mm, measured under the head to the end of the threads. These bolts are made in Germany and have a black oxide finish. Head marking is the German manufacturer "Graeka".

These bolts are used in various applications on 356 models such as:

• Trans ground strap
• Front fender support