Cleveland C58616 Spiral Flute Tap 1/2"-20 UNF Bottoming 3 Flutes Bright

1/2"-20 UNF Bottoming Tap

The Cleveland C58616 is a spiral flute tap designed to cut 1/2"-20 UNF threads in through-holes and blind holes. Its three-flute geometry and right-hand thread direction suit general-purpose threading tasks on compatible workpieces. The bright, uncoated high-speed steel construction provides standard wear resistance for routine maintenance and repair work. This tool targets machinists and technicians who need to create internal threads to a 2B class of fit.

H3 Thread Limit and 75 % Drill Size

The tap conforms to an H3 thread limit and requires a 75 percent thread drill size of 11.40 mm for proper hole preparation. Its thread length measures 15/16 in within an overall length of 3 3/8 in. The bottoming chamfer allows threading close to the bottom of a blind hole, but the fixed H3 limit means the tool cannot compensate for hole-size variation beyond its tolerance band. Users must match the drill size precisely to achieve the specified class of fit.

Verify Hole Depth and Material Suitability

Before ordering, confirm that your workpiece material is compatible with uncoated high-speed steel and that the 15/16 in thread length meets your depth requirement. The bottoming style demands sufficient hole clearance for chip evacuation in blind-hole applications. Ensure your holding equipment accommodates the tap's shank dimensions and that the 1/2"-20 UNF thread specification matches the fastener you intend to use.