metric hex bolts , partially threaded ( din 931): a hex machine bolt with metric thread pitch. Generally manufactured in accordance with din standard 931 or iso standard 4014 
an externally threaded fastener, with a trimmed hex head, but with no washer face on the bearing surface. (its body tolerances are not as close as those of a hex cap screw.) 
used in a variety of general purpose applications (depending on the grade of the material) in situations where dimensional tolerances are not as critical. 

• grade: ss 304
• grade ss 316
• high tensile gr. 8.8 / gr. 10.9
• mild steel gr. 4.6 / gr. 5.6

metric hex bolts , partially threaded ( din 931): a hex machine bolt with metric thread pitch. Generally manufactured in accordance with din standard 931 or iso standard 4014 
an externally threaded fastener, with a trimmed hex head, but with no washer face on the bearing surface. (its body tolerances are not as close as those of a hex cap screw.) 
used in a variety of general purpose applications (depending on the grade of the material) in situations where dimensional tolerances are not as critical. 

• grade: ss 304
• grade ss 316
• high tensile gr. 8.8 / gr. 10.9
• mild steel gr. 4.6 / gr. 5.6