National Coarse & Fine (UNC & UNF) GH11 Oversize Spiral Point Taps
Our standard H11 taps are Spiral Point style taps
Oversize taps are commonly used to tap holes that will be heat treated after tapping or will be plated, thus the need for oversize thread diameters
H11 tap is +0.005” oversize.
Oversize ranges can be specified to best suit the application (+.003”; +.005”; +.010”; +.127mm; +.076mm; and so on.) Please contact us for a custom quote.
Don't forget to use a good cutting lubricant
SPIRAL POINT TAPS
As to general physical dimensions, spiral point taps are identical with the standard hand tap. However, the spiral point tap has the cutting face of the first few threads cut at a pre-determined angle relative to the tap's axis angle to force the evacuation of chips ahead of the cutting action. This feature, plus the excellent shearing action of the flute, make spiral pointed taps ideal for production tapping of through holes. Typically, this type of tap has a shallower flute passage than conventional taps. This gives the spiral point tap more cross-sectional area, which means greater strength, allows higher tapping speeds, and requires less power to drive.