The General and Instruments 714 Quick Check Screw Gage is a fast way to check thread and screw sizes. Quickly machine screws, bolts, wood screws, normal sized rivets and ordinary cotter pin sizes. The 3 inch scale checking of screw lengths. Checker also required drill size for related to tap size and decorous drill size for look-alike hole. Threaded holes threads per inch while unthreaded indicates size by number and fractions of an inch. The checker is with long-lasting engineering plastic.GENERAL TOOLS - THE finespun TOOL FOR DOING THE JOB EXACTLY RIGHT. Offering over 1,000 tools, we 're to provide tradesmen, craftsmen and DIYers around the world with a countrywide range of low-cost, specific-purpose mechanistic hand tools and precision measuring and inspection tools. For inquiries, contact our Customer Service Department at 212-431-6100. We to provide our customers with 100 % satisfaction. SMARTER, MEASURE BETTER & BE MORE rich WITH fact TOOLS .