Drilling Product Catalog

DRILLING | Opening Drill®: Large Diameter Indexable Carbide Insert Drilling System

Minimum Pilot Hole Diameter

Pre-drilled part or core

Opening Drill

Metric Minimum Pilot Hole Diameter

Minimum Pilot Hole Diameter = Finish Diameter - C To open an existing diameter hole to 69.85 mm diameter, an OP2 tool would be used. The minimum pilot hole diameter would be: 69.85 mm - 47.75 = 22.10 mm

Opening Drill Series

Drill Diameter Range

C

OP1 OP2 OP3 OP4

50.80 - 63.50 63.50 - 76.20 76.20 - 104.65 104.65 - 142.75

47.75 47.75 47.75 68.07

Imperial Minimum Pilot Hole Diameter

Minimum Pilot Hole Diameter = Finish Diameter - C To open an existing diameter hole to 2.7500" diameter, an OP2 tool would be used. The minimum pilot hole diameter would be: 2.7500" - 1.880 = 0.8700"

A70

Opening Drill Series

Drill Diameter Range

C

OP1 OP2 OP3 OP4

2.0000 - 2.5000 2.5000 - 3.0000 3.0000 - 4.1200 4.1200 - 5.6200

1.880 1.880 1.880 2.680

A70: 15

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