Tri-Clamp x Male NPT (21MP)

  • Sanitary Tri-Clamp to Male NPT Adapter
  • Available in 304 & 316L Stainless Steel
  • Surface Finish: 32 Ra ID/OD
  • View Sizes and Dimensions
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The Tri-Clamp x Male NPT Adapter, which provides a secure, rust-resistant solution for simple conversions and hose adaptions.

One of our most widely used stainless steel tube fittings, this product remains a consistent choice among both amateurs and professionals due to its reliability and secure hold. All Tri-Clamp x Male NPT Adapters are composed of long-lasting stainless steel and are available in two alloys: 304 and 316L. The adapter features an Outside Diameter (OD) measurement from ½” up to 4”. The male NPT threaded connection varies in size from as small as ¼” up to 1”, meeting an array of needs because of its broad number of uses. With this number of combinations, the Tri-Clamp x Male NPT Adapter can serve many bath and sanitary fitting functions and is safe for use in industries such as dairy, food and beverage, and pharmaceuticals. All Tri-Clamp x Male NPT Adapters are 21MP and use the industry-standard tri-clamp for strong, leak-free connections. eve Please see the conversion chart listing the Sanitary Size, Outside Diameter of Flange End, Inside Diameter of Tube, and Outside Diameter of Tube, providing accurate measurements and ensuring that the Tri-Clamp x Male NPT Adapter will provide a superb fit. With over 20 combinations in varying sizes, the Tri-Clamp x Male NPT Adapter is the adapter of choice in most circumstances and has part compatibility with Bradford, Alfa Laval, Dixon, and more. Tapered for sealing, often without any thread sealant; for connections in nearly every type of service. [Learn More]

Male NPT x Clamp Adapters Part Numbers & Dimensions

Part Number Cross Reference
Sanitary Fittings Bradford Alfa Laval Waukesha Cherry VNE Top Line Andron®
21MP 21MP 21MP 21MP EG21 21MP AC21
Male Threaded Clamp Adapter Dimensions
Tri-Clamp x NPT Size Part Number Dimensions Line Drawing
304L 316L A B
1/2" x 1/4" N/A 21MP-.50X.25-316 2.000" 0.782" PDF
1/2" x 3/8" N/A 21MP-.50X.375-316 2.000 0.782 PDF
1/2" x 1/2" N/A 21MP-.50-316 2.000 0.782 PDF
1/2" x 3/4" N/A 21MP-.50X.75-316 2.000 0.5942 PDF
1/2" x 1" N/A 21MP-.50X1-316 1.625 0.782 PDF
3/4" x 1/4" N/A 21MP-.75X.25-316 2.000 0.794 PDF
3/4" x 3/4" N/A 21MP-.75-316 2.000 0.794 PDF
3/4" x 1" N/A 21MP-.75X1-316 2.250 0.794 PDF
3/4" x 1.5" N/A 21MP-.75X1.5-316 2.250 0.794 PDF
1" x 1/4" NA 21MP-1X25-316 2.187 0.793 PDF
1" x 1/2" 21MP-1X.50-304 21MP-1X.50-316 2.187 0.793 Request Drawing
1" x 3/4" NA 21MP-1X75-316 2.187 0.793 PDF
1" x 1" 21MP-1-304 21MP-1-316 2.250 0.985 PDF
1" x 2" 21MP-1X2-304 21MP-1X2-316 2.250 0.985 PDF
1 1/2" x 1/8" -- 21MP-1.5X.125-316 2.187 0.985 Request Drawing
1 1/2" x 1/2" 21MP-1.5X.50-304 21MP-1.5X.50-316 2.187 0.985 PDF
1 1/2" x 3/4" N/A 21MP-1.5X.75-316 2.187 0.985 PDF
1-1/2" x 1" 21MP-1.5X1-304 21MP-1.5X1-316 2.313 0.984 PDF
1-1/2" x 1 1/4" 21MP4-1.5X1.25-304 21MP-1.5X1.25-316 2.438 1.008 PDF
1-1/2" x 1 1/2" 21MP-1.5-304 21MP-1.5-316 2.438 1.025 PDF
1-1/2" x 2" 21MP-1.5X2-WF-304 21MP-1.5X2-WF-316 2.625 1.058 PDF
2"x 1" 21MP-2X1-304 21MP-2X1-316 2.469 1.058 PDF
2"x 1 1/2" 21MP-2X1.5-304 21MP-2X1.5-316 2.469 1.058 PDF
2"x 2" 21MP-2-304 21MP-2-316 2.656 1.058 PDF
2-1/2" x 2" 21MP-2.5-304 21MP-2.5-316 2.781 1.058 PDF
2-1/2" x 2 1/2" 21MP-2.5-304 21MP-2.5-316 3.281 1.571 PDF
3" x 2" 21MP-3x2-304 21MP-3X2-316 3.000 1.058 PDF
3" x 3" 21MP-3-304 21MP-3-316 3.500 1.634 PDF
4" x 4" 21MP-4-304 21MP-4-316 3.155 1.734 PDF

Watch How to Measure Tri-Clamp Fittings

Tri-Clamp Fittings and Gasket Sizing Guide

Sanitary Fitting Dimensions
Sanitary Size OD of Flange End ID of Tube OD of Tube
1/2″ 0.992 0.370 0.500
3/4″ 0.992 0.620 0.750
1″ 1.984 0.870 1.000
1 1/2″ 1.984 1.370 1.500
2″ 2.516 1.870 2.000
2 1/2″ 3.047 2.370 2.500
3″ 3.579 2.870 3.000
4″ 4.682 3.834 4.000
6″ 6.562 5.782 6.000
8″ 8.602 7.782 8.000
10″ 10.570 9.782 10.000
12″ 12.570 11.760 12.000
21MP4-050 21MP4-075 21MP4-100 21MP4-150 21MP4-200 21MP4-250 21MP4-300 21MP4-400 21MP6-050 21MP6-075 21MP6-075050 21MP6-100 21MP6-100050 21MP6-100075 21MP6-150 21MP6-150050 21MP6-150075 21MP6-150100 21MP6-150125 21MP6-200 21MP6-2000100 21MP6-2000150 21MP6-200050 21MP6-200075 21MP6-200100 21MP6-200150 21MP6-250 21MP6-250150 21MP6-250200 21MP6-300 21MP6-300200 21MP6-400 21MP6-400300

Questions & Answers 5

Questions and answers of the customers

  1. Q Clamp 1.5" Is there an adapter male or female for 1/8" NPT?... Read more
    A This is a custom item but we can manufacture it for you. 1 1/2" Tri-Clamp x 1/8" Male NPT and 1 1/2" Tri-Clamp x 1/8" Female NPT. Quantity discounts are available for this item so please contact us for more information.
  2. Q I am looking for a part number for the clamp x NPT combination 2 1/2" x 2" but it is not included...... Read more
    A The part number you are looking for is 21MP-2.5x2-316. I have added it to our table of part numbers online along with a digital download line drawing.
  3. Q Is this product 3A Certified?... Read more
    A The design of this fitting does not meet 3A Specification Standards. Any fitting with threads like this one cannot be considered a 3A Sanitary.
    A The design of this fitting does not meet 3A Specification Standards. Any fitting with threads like this one cannot be considered a 3A Sanitary. 3A requires fittings to be easily cleaned and maintained. The thread design does not allow for that according to the specification.
  4. Q What's the difference between NPT & NPS threads... Read more

    NPS = National Pipe Straight

    NPT = National Pipe Thread

    Both NPT and NPS have the same thread angle, shape, and pitch (threads per inch). However, NPT threads are tapered and NPS threads are straight (parallel). Both threads have a 60° included angle and have flat peaks and valleys.

    Tapered Pipe Thread is commonly found on ends of pipe, nipples and fittings (i.e. couplings, elbows, tees, etc.). Note: Sharply angled threads are very critical to joint being tight with no leaks. Thread sealant or tape is typically required to complete the seal. Straight Pipe Threads need a gasket or O-ring to create a seal.

    While NPT and NPS threads will engage, they do not seal properly with each other.

  5. Q Do you offer different clamp x NPT size combinations like 1 1/2" x 2"?... Read more
    A Different size combinations are available however these items are not stocked and the typical lead time for these products is about 1 - 2 weeks. Please call us for special orders and we'll let you know what we can do for timing and pricing. Thanks!

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