DOUBLE SIDED TOOL: This guide features a Tap Drill Depth Chart, decimal conversions from 1/64" to 63/64" and a ruler graduated in 64ths FRONT SIDE: Front side has a machine screw size tap drill chart for recommended 75% depth thread. BACK SIDE: Features a decimal equivalents table in 64ths from 1/64" to 63/64". 6 INCH RULER: Graduated in 64ths. WORKS WITH: National Fine, National Course, American Standard Pipe and metric threads. ESSENTIAL TOOL: Essential tap drill and decimal equivalents reference table for toolmakers, machinists and mechanics. GENERAL TOOLS: We're a recognized leader in designing and developing specialized precision tools dedicated to delivering exceptional customer service. We encourage artisans and DIYers to work smarter, measure better, and repair more productively. GN715 Features: -Reference table. -Essential tap drill and decimal equivalents reference table for toolmakers, machinists and mechanics. -Front has machine screw size tap drill chart for recommended 75% depth thread. -Back has decimal equivalents table in 64ths from 0.02'' to 0.98''. Dimensions: Overall Product Weight: -0.01 Pounds.