Grade 10.9 Countersunk Screws Hex Socket Flat Head Allen Key Bolts Nickel M5 M6 M8. Pitch：0.8mm（M5）/1mm（M6）/1.25mm（M8）. The product is made of 10.9 grade high strength carbon steel, which has the characteristics of high toughness, good cold and hot working performance and excellent machinability.
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