Cutting Diameter Description Series Page Length BTA Indexable Drills - .984 - 2.094 100 x D Single Tube System - Outer Four TBTA-C_SE4 621 Start Thread BTA Indexable Drills - .984 - 2.094 100 x D Double Tube System - Outer Four TBTA-C_DE4 622 Start Thread BTA Indexable Drills - 1.181 - 2.559 100 x D Single Tube System - Outer Four TBTA-D_SE4 625 Start Thread BTA Indexable Drills - 1.181 - 2.559 100 x D Single Tube System - Outer Four TBTA-D_DE4 626 Start Thread BTA Indexable Drills for Large 2.441 - 7.244 100 x D Diameters - Single Tube System - TBTA-L_SE4 630 Outer Four Start Thread BTA Drills Brazed .496 - 1.559 100 x D Single Tube System - Outer Four BTA_SE4 633 Start Thread BTA Drills Brazed 1.559 - 2.559 100 x D Single Tube System - Outer Four BTA_SE4 634 Start Thread BTA Drills Brazed .725 - 1.559 100 x D Double Tube System - Outer Four BTA_DE4 635 Start Thread BTA Drills Brazed 1.559 - 2.559 100 x D Double Tube System - Outer Four BTA_DE4 636 Start Thread BTA Drills Brazed .496 - .787 100 x D Single Tube System - Outer Two BTS_SE4 637 Start and Four Start Thread 485