Atoplee 5pcs Machine Screw Metric Thread Plug Taps Set M3 M4 M5 M6 M8 MaterialHSSColor Silver Thread Diameter/Shank Diameter3mm(M3)  4mm(M4)5mm(M5) 6mm(M6)8mm(M8) Total Length 49mm / 1.9"(M3)56mm / 2.2"(M4) 65mm / 2.5"(M5) 70mm(M6) 62mm/ 2.44"(M8) Square Head Size (L*W)2.5 x 2.5mm / 0.1" x 0.1"(M3)3 x 3mm / 0.12" x 0.12"(M4) 4 x 4mm / 0.16" x 0.16"(M5) 5 x 5mm(M6) 4.8 x 4.8mm/ 0.19" x 0.19" (M8) Package Included: 5pcs Machine Screw Thread Metric Plug Tap 2.5 x 2.5mm / 0.1&#034; x 0.1&#034;(M3) 3 x 3mm / 0.12&#034; x  0.12&#034;(M4) 4 x 4mm / 0.16&#034; x 0.16&#034;(M5) 5 x 5mm(M6) 4.8 x 4.8mm/ 0.19&#034; x  0.19&#034; (M8)