GTI - TAPPING ATTACHMENT 58-60 HRc Ra 4µin L2 L1 Ref L Ref D1 D C T Designation Tap Capacity Range D1 L2 L1 L D T C GTI ER11 ST5/8 #3-1/4” .022- .278 .625 6.00 - .75 .63 .24 .12 GTI ER16 ST3/4 #6-3/8” .022- .396 .750 3.15 1.61 .95 1.10 .32 .12 GTI ER20 ST3/4 #8-1/2” .041- .514 .750 3.15 1.89 1.06 1.34 .32 .12 GTI ER25 ST1 #10-5/8” .041- .632 1.000 3.15 2.01 1.18 1.66 .36 .16 GTI ER32 ST1 1/4-3/4” .080- .789 1.000 3.15 2.91 1.18 1.97 .36 .16 GTI ER40 ST1-1/4 5/16-1-3/8” .120-1.025 1.250 3.15 3.54 1.81 2.36 .36 .16 834