1/4 x 2 1/2 Mushroom Spike Zinc Plated (100)

a new plating that is 7x more corrosion resistant than standard zinc plating

hardness will range from HRC 31-39

7/8-9 x 4 Hex Cap Screw SS 18-8 (A2)

15/32 Cobalt Heavy Duty Jobber Drill Bit (6) 1/2-13 Grade 5 Hex Cap Screws Zinc Plated 1/4 x 2 1/2 Mushroom15 32 Cobalt Heavy Duty Jobber Drill Bit . Heavy duty construction made to Type J aircraft specifications. Used for drilling holes in hard, tough materials such as stainless steel, titanium, high temperature and high strength alloys. High red hardness of cobalt permits speeds 30% greater than standard heavy duty split point (HSS) drills.