Tri-Clamp x Male NPT (21MP)

(5 customer reviews)

  • Sanitary Tri-Clamp to Male NPT Adapter
  • Available in 304 & 316L Stainless Steel
  • Most items are in stock and ship same day
  • 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.

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.

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 1.625 0.782
1/2″ x 3/8″ N/A 21MP-.50X.375-316 1.625 0.782
1/2″ x 1/2″ N/A 21MP6-050 1.625 0.782
1/2″ x 3/4″ N/A 21MP-.50X.75-316 1.625 0.782 Request Drawing
1/2″ x 1″ N/A 21MP-.50X1-316 1.625 0.782 Request Drawing
3/4″ x 3/4″ N/A 21MP6-075 1.787 0.794
1″ x 3/4″ NA 21MP6-100075 2.187 0.793
1″ x 1″ 21MP4-100 21MP6-100 2.250 0.985
1-1/2″ x 1″ 21MP-1.5X1-304 21MP-1.5X1-316 2.313 0.984
1-1/2″ x 1 1/4″ 21MP4-1.5X1.25-304 21MP6-1.5X1.25-316 2.438 1.008
1-1/2″ x 1 1/2″ 21MP4-150 21MP6-150 2.250 1.025
2″x 2″ 21MP4-200 21MP6-200 2.638 1.058
2-1/2″ x 2 1/2″ 21MP4-250 21MP6-250 2.875 1.571
3″ x 3″ 21MP4-300 21MP6-300 3.070 1.634
4″ x 4″ 21MP4-400 21MP6-400 3.155 1.734 Request Drawing

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

5 reviews for Tri-Clamp x Male NPT (21MP)

  1. Ralph Johnson (store manager)

    Verified reviewVerified review - view originalExternal link

    Outstanding customer service. Fast shipping. Parts arrived in perfect condition.

  2. Anonymous (verified owner)

    Verified reviewVerified review - view originalExternal link

  3. Greg St Amour (verified owner)

    Verified reviewVerified review - view originalExternal link

  4. Eddie V. (verified owner)

    Verified reviewVerified review - view originalExternal link

  5. eric watts (verified owner)

    Verified reviewVerified review - view originalExternal link


Questions and answers of the customers

  1. 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.
  2. A 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.
  3. 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!