COUNTER SINK BIT: HSS 1″ THREE FLUTE 1/2″ SHANK – 90 DEG

** This Three flute countersink bit is manufactured from quality HSS-M2
* This offers durability and long service life – Comes with 1/2″ shank
T* The number on a countersink—60°, 82°, 90°, 100°, 120°—is the included angle: the full angle across the cone, tip to tip, not the angle from the centerline. A 90° countersink has 45° of flank on each side.

* * That number is not a style choice. For anything that receives a flat-head screw, it is dictated by the fastener standard the screw was made to, and the two do not mix:

82* 82 Geg —inch flat-head screws. The angle specified for inch-series flat countersunk heads under ASME B18.6.3. If the screw came out of a bin marked 10-32 or 1/4-20, this is the one.

90* 90 Deg — metric flat-head screws. The angle for metric countersunk heads (ISO 7046, DIN 965). It is also the workhorse for non-fastener jobs: chamfering a hole before tapping, breaking an edge, or opening a mouth so a pin starts straight.

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