Drill America 1-3/8ft-12 UNF High Speed Steel Bottoming Tap

Our review of the Drill America 1-3/8'-12 UNF High Speed Steel Bottoming Tap finds it best suited for machinists and hobbyists who need to generate threads to the bottom of a blind hole or re-thread damaged fasteners. The bottoming style design lets the tool finish threads as close to the hole bottom as possible, which is the single biggest reason to choose this tap for repair work or tight-depth applications. It is a simple, uncoated high speed steel hand tap intended for hand or machine tapping and offers straightforward performance when used within its expected limits.

Key Features

• Bottoming style: Designed to generate full threads to the bottom of a blind hole so you can seat a fastener deeply.
• High speed steel: The HSS substrate balances edge sharpness and toughness for general machine tapping and hand use.
• Uncoated finish: The tool comes without additional coatings, making it suitable for a range of materials and avoiding coating-related galling issues.
• Single-piece supply: Sold as a single bottoming tap so you can replace a worn bottom tap or complete a set that includes taper and plug styles.
• Machine or hand use: The tap works for manual tapping or under power in general machine or CNC tapping setups when used with proper feeds and lubrication.

Who It's For

The Drill America bottoming tap is ideal for metalworkers, maintenance techs, and fabricators who routinely need to create or restore threads in blind holes, especially where a fastener must reach the bottom of the hole. It is also a practical choice for hobby machinists working with materials like aluminum and mild steel who value a sharp HSS cutting edge.

Those who need coated taps for extended life in abrasive or high-temperature production environments, or who frequently thread hardened steels, should look to specialty coated or ground taps designed for those specific conditions instead of an uncoated HSS hand tap.

Pros & Cons

Pros

• Sharp HSS cutting edge makes initial thread engagement and cutting in softer metals straightforward.
• Bottoming geometry allows threading to the hole bottom for clean, deep fastener seating.
• Versatile for hand tapping or use under power in general machine or CNC applications.

Cons

• Uncoated HSS can wear faster than coated alternatives and may not be ideal for very hard or abrasive materials.
• Some users report breakage when used improperly or in very hard materials, so careful technique is required.

Specifications

Product name	1-3/8'-12 UNF High Speed Steel Bottoming Tap
Thread size	1-3/8'-12 UNF
Material	High Speed Steel (HSS)
Style	Bottoming tap
Finish	Uncoated
Intended use	Hand tapping, general machine tapping, CNC tapping

Our Verdict

The Drill America 1-3/8'-12 UNF HSS bottoming tap is a practical, value-focused choice for anyone needing to cut threads to the bottom of a blind hole or re-thread damaged threads in common metals. It delivers sharp cutting performance and versatility for hand or machine use, though buyers should accept the tradeoff of an uncoated HSS tool and use careful technique to avoid breakage in harder materials.

Frequently Asked Questions

Can this tap be used by hand?
Yes, the HSS hand tap is intended for hand use as well as machine or CNC tapping when used with appropriate lubrication and proper feed rates.

Is the tap coated for extra durability?
No, this bottoming tap is uncoated, offering the base HSS substrate without additional surface treatments.

Will it cut threads to the bottom of a blind hole?
Yes, the bottoming style is specifically designed to generate threads up to the bottom of a blind hole for deep fastener engagement.