Screw machine thread tap drill bit set — HSS with straight spiral flute Key benefits Accurate hole sizes for reliable threading: sized specifically for screw machine threading tasks to produce consistent, repeatable holes ready for taps. Cleaner cutting and fewer interruptions: the straight spiral flute design promotes efficient chip evacuation to help prevent clogging and reduce the chance of tap binding. Longer tool life and dependable performance: made from highspeed steel (HSS) for good hardness and wear resistance in routine production and maintenance use. What’s included Set of drill/tap bits in the following sizes: 1/840, 3/1624, 1/420, 5/1618, 3/816, 3/410, 7/89. Material and design Highspeed steel (HSS): balances hardness and toughness for extended service in metalworking. Straight spiral flute: engineered to move chips away from the cut efficiently, improving surface quality and reducing interruptions. Ideal applications Screw machine production: use in single- and multi-spindle screw machines to prepare accurate holes for threading operations. Small-part manufacturing and prototyping: drilling precise pilot holes for fasteners in production runs or prototype assemblies. Maintenance and repair: ideal for on-site or workshop tasks where reliable, repeatable threaded holes are needed. Compatibility and performance notes Designed for screw machine applications and similar setups that require precise drill sizes for threading. Use appropriate speeds, feeds, and lubrication for the material being drilled to maximize performance and tool life. Why choose this set Purpose-built sizes and HSS construction deliver consistent, practical performance for threading preparation. Simple, effective flute geometry reduces chip-related interruptions and supports cleaner holemaking. Package and usage tips Verify each bit size before use to match the required tap drill for your threading dimensions. Apply cutting fluid and moderate feed rates for best results in metalworking.