IRWIN 1904ZR Threading Tool
- Size: 3/8" - 18NPT
- Measurement System: Imperial
- Material: Plastic
- Number Of Pieces: 1
Last refreshed Aug 4, 2026 · Based on the Amazon listing and published specifications, not hands-on testing.
Given the plastic build, this reads as a thread gauge or fitting reference for the 3/8-18 NPT standard rather than a cutting tap, so match expectations to that use.
As an Amazon Associate I earn from qualifying purchases. ProductDome earns a commission when you buy through links on this page.
ASIN: B000UE1VCMModel: 1904ZRCategory: Threading Tools
Overview
Sized for 3/8 inch, 18 NPT pipe threads, the Irwin 1904ZR threading tool is built in plastic with a brushed finish and weighs 1.6 ounces.
The plastic construction listed here points to this being a thread gauge or reference piece rather than a metal cutting tap, since taps that actually cut threads into pipe are normally hardened steel. 3/8-18 NPT is a standard pipe thread size used across plumbing and pneumatic fittings, so this tool is likely meant to check or match that thread rather than cut it fresh. The listing does not confirm length or exact use case beyond size and material.
- 3/8 inch, 18 NPT sizing
- Plastic construction
- Brushed finish
- 1.6 ounce weight
Who it's for
Fits anyone working with 3/8-18 NPT fittings who needs a tool matched to that exact thread size for checking or reference. Not a fit for anyone expecting a hardened steel tap for cutting new threads into pipe.
Pros and cons
- Sized precisely to the 3/8-18 NPT standard
- Light at 1.6 ounces for handheld use
- Plastic build limits it to gauging rather than cutting threads
- No length or thread-count detail given
- Not a substitute for a hardened steel tap
Performance notes
3/8-18 NPT is a common pipe thread size in plumbing and pneumatic work, so this tool is sized to match or check that standard directly. At 1.6 ounces and built in plastic, it is light enough for handheld reference use but not built like a hardened cutting tap. The brushed finish is cosmetic rather than functional for thread cutting.
Specifications
| Brand | Irwin |
|---|---|
| Model | 1904ZR |
| Dimensions & fit | |
| Size | 3/8" - 18NPT |
| Item Weight | 0.1 poundslower than 50% of 43 threading tools |
| Product Dimensions | 2.6 × 7.5 × 0.7 inches |
| Power & efficiency | |
| Power Source | Corded Electric |
| Construction & materials | |
| Material | Plastic |
| Color | Silver |
| Finish | Brushed |
| Included components | |
| Number Of Pieces | 1 |
| Batteries Included | No |
| Included Components | Irwin TAP 3/8"-18NPT Taper |
| Item Package Quantity | 1 |
| Warranty & support | |
| Warranty Description | Warranty |
| Other details | |
| Measurement System | Imperial |
| Batteries Required | No |
| Part Number | 1904 |
| Item Model Number | 1904ZR |
| Shape | Rectangular |
| Pattern | Solid |
| Style | Classic |
Closest rivals on specs
Walton Tools WLT10314 4-Flute Tap Extractor 5/16 Inch- Item Weight 0.1 vs 0.08 pounds (+25%)
Bosch BPT38F16 Fractional Plug Tap 3/8-16- Item Weight 0.1 vs 0.08 pounds (+25%)
Drill America DWT54455 Bottoming Tap 1/4-20 UNC- Item Weight 0.1 vs 0.07 pounds (+43%)
Frequently asked questions
What thread size does the Irwin 1904ZR fit?
It is sized for 3/8 inch, 18 NPT pipe threads.
Is the Irwin 1904ZR made of metal?
No, the listing specifies a plastic construction with a brushed finish.
How much does the Irwin 1904ZR weigh?
It weighs 1.6 ounces.