52-Piece Precision Thread Checker Set: Industry's one of most comprehensive bolt size finder tool with 27 SAE & 25 metric gauges—covers 4-40 to 1"-12 bolts and M2.5-M20 fasteners. This nut and bolt thread checker ensures you never struggle with missing sizes for DIY repairs or pro projects! Conquer Tight Spaces with Detachable Gauges: Uniquely designed thread checker slides out individually from the foam case. Easily test bolts in engines, machinery, or hard-to-reach spots—no bulky tools to maneuver! Laser-Organized for Instant Matching: Red/Blue color-coded thread gauge sae and metric(Metric/SAE) + matching screw size chart. Foam slots & labels align 1:1 for bolt and nut identifier gauge—find sizes at a glance!Laser-etched markings on thread pitch gauge resist wear for lifelong clarity. Guaranteed Precision: ISO & ANSI Certified:Meets Internal/External Threads, ISO 965-1 6H/6g & ANSI B1.1 Class 2B/2A. CNC-machined aluminum for reliable bolt measuring tool accuracy. Thread checker standard and metric resisting oxidation and wear - built to last through heavy workshop use. 5-Second Nut/Bolt Identification: Screw → Match → Done! This thread pitch gauge metric and SAE replaces hardware store trips. Organize mixed fasteners instantly—perfect for mechanics’ shops, garages, and DIY toolkits! 52-Piece Precision Thread Checker Set: Industry's one of most comprehensive bolt size finder tool with 27 SAE & 25 metric gauges—covers 4-40 to 1"-12 bolts and M2.5-M20 fasteners. Never struggle with missing sizes for DIY repairs or pro projects!