Viking Drill and Tool St. Paul MN
America's Finest High-Speed Steel Cutting Tools™

Proudly Manufactured in the USA

  • 240-CN CN-TECH™ Cryogenic Nitrided Jobber Drill
  • Type 40-AG HSS Super Premium Combination Drill & Tap
  • HSS Heavy-Duty NAS 907B Titanium Carbon Nitride
  • HSS Heavy-Duty NAS 907B Titanium Aluminum Nitride
  • M42 TiN Coated NAS 907B
  • Type
  • Cobalt Jobber Drill Bits NAS 907J
  • Cobalt Screw Machine Drill Bits NAS 907J
  • Type XGT-AG Extra Length Drill
  • HSS 118° Point Black Oxide

TAP FEEDS and SPEEDS

Basic Anatomy Taps Diagram

How to Tap Effectively and Optimize Tool Life

To minimize tapping issues the following rules should be followed:
• Use a pitch controlled tapping attachment.
• Choose the correct lubricant (Choose – Ultra S/P ™ Super Premium).
• Use the correct tapping drill size and type of tap.
• Choose the correct Speeds and Feeds.
• Keeping taps sharp, check tap for wear.
• Ensure accurate alignment.
• Check hardness of material, especially when changing batches of material.
Chamfer Tap Style Diagram

Tapping Speed can be calculated using: (Use Table below)
RPM = Feed Speed (SFM) / 0.26 x Tap's Outer Dimension

Tapping speeds should be " DECREASED "  if
• Lubricant is Poor or Flow is Restricted.
• Bottom lead or Spiral flute taps are used.
• Thread depth ( % ) increase.
• Thread pitch is course.
• Cutting taper threads (50% Normal Speed).

Tapping speeds can be " INCREASED "  if
• Thread Depth decreases.
• Thread Pitch is fine.
• Coolant flow and Quality is Good.
• Spiral point taps are used.

Tapping Speeds
Proper tapping speeds are very important in obtaining efficient tapping results. The optimum speed for tapping is highest speed that conditions permit, consistent with acceptable tool life. Speeds must be reduced as length of hole increases. Holes, taps with tapered chamfers are able to operate faster than taps with bottoming chamfers. Vertical tapping speeds can be increased, compared to horizontal tapping.

Recommended Feeds and Speeds table below suggests a "starting point" for selecting the speed to operate the tap.

Tapping Formulas and Calculations

RPM for UNC/UNF
Viking Drill and Tool - RPM for UNC/UNF

Feed Rate for UNC/UNF Taps
Viking Drill and Tool - Feed Rate for UNC/UNF

RPM for M/MF Taps
Viking Drill and Tool - RPM for M/MF Taps

Feed Rate for M/MF Taps
Viking Drill and Tool - Feed Rate for M/MF Taps

Recommended Feeds and Speeds (SFM) into Material

Material Recommended Feeds and Speeds (SFM)
Aluminum - Cast Alloys 60
Aluminum - Diecast Alloys 70
Aluminum - Wrought Alloys 80
Brass 60-100
Bronze 30-40
Copper 60-80
Gun Metal 50-60
Cast Iron - Grey 30-60
Cast Iron - Ductile 50
Cast Iron - Alloys 15-30
Malleable Alloy 20-40
Magnesium Alloys 50-70
Nickel Alloys 10
Nimonic Alloys 10-12
Mild Steel 30-50
Steel - Medium Carbon 35
Tool Steel 15-25
Cast Steel 25
Titanium Alloys 10
Stainless Steel - 300 Series 10-20
Stainless Steel - 400 Series 15
Plastic 50-70
Zinc - Diecasting 80