Name: Forged Threaded Hex Reducing Bushing
Brand: Cunimet Alloy International

Product Overview

Forged Threaded Hex Reducing Bushing

The Forged Threaded Hex Reducing Bushing is a single-piece fitting that reduces from one threaded pipe size to a smaller threaded pipe size within a single screwed connection. The outer body carries male NPT threads at the larger pipe size, which screw into a female-threaded fitting outlet. The inner bore carries female NPT threads at the smaller pipe size, into which the smaller male-threaded pipe or nipple is screwed. The hex profile on the body allows spanner engagement for tightening.

The bushing is the most compact method of reducing bore size in a threaded piping system, requiring no additional fitting or nipple between the two different pipe sizes. It sits entirely within the female outlet of the larger fitting, keeping the overall assembly compact. Cunimet Alloy International manufactures threaded hex bushings through closed-die forging in all standard ASME B16.11 size combinations, with both the male external thread and the female internal thread precision-cut on CNC turning centres to ASME B1.20.1 tolerances.

ASME B16.11 ASME B1.20.1 (NPT) Male NPT OD (Large) Female NPT ID (Small) Hex Body for Wrench All Standard Combos

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ASMEStandardB16.11

M/FThread ConfigMale OD / Female ID

3/4–4"Large End RangeNPS (Male OD)

HexBody ProfileWrench Engagement

3Material GradesSS / Duplex / S.Duplex

Technical Dimensions

Threaded Hex Bushing — ASME B16.11 Size Combinations

“L” = Overall length. “W” = Hex width across flats (governed by the large male end size). Large end = male NPT thread on body OD. Small end = female NPT thread in bore. Thread form per ASME B1.20.1. All dimensions in millimetres.

Large Male NPS	Small Female NPS	L (mm)	Hex W (mm)	Large TPI	Small TPI
3/4"	1/2"	19	34	14	14
1"	3/4"	22	41	11.5	14
1"	1/2"	22	41	11.5	14
1-1/4"	1"	22	51	11.5	11.5
1-1/4"	3/4"	22	51	11.5	14
1-1/4"	1/2"	22	51	11.5	14
1-1/2"	1-1/4"	25	57	11.5	11.5
1-1/2"	1"	25	57	11.5	11.5
1-1/2"	3/4"	25	57	11.5	14
2"	1-1/2"	29	68	11.5	11.5
2"	1-1/4"	29	68	11.5	11.5
2"	1"	29	68	11.5	11.5
2-1/2"	2"	35	83	8	11.5
2-1/2"	1-1/2"	35	83	8	11.5
3"	2-1/2"	38	95	8	8
3"	2"	38	95	8	11.5
4"	3"	44	117	8	8
4"	2-1/2"	44	117	8	8
4"	2"	44	117	8	11.5

Standard combinations per ASME B16.11. Non-standard combinations available on request. BSP threads to BS EN 10226 available. All dimensions in millimetres.

Available Materials

Material Grades for Threaded Hex Bushings

Grade 01

Stainless Steel 304 / 316

Austenitic stainless steel hex bushings for bore reduction in chemical, pharmaceutical, food and water treatment screwed piping systems. SS 316 preferred wherever pitting or crevice corrosion in the thread engagement zone is a risk.

ASTM A182 F304ASTM A182 F316ASME B16.11

Grade 02

Duplex Steel

High-strength duplex alloy hex bushings for bore reduction at instrument manifold connections, chemical injection skids and offshore process screwed piping where the male-to-female thread interface must resist chloride corrosion throughout service life.

ASTM A182 F51UNS S31803UNS S32205

Grade 03

Super Duplex Steel

Premium super duplex hex bushings with PREN greater than 40 for bore reduction connections in seawater service, offshore topsides screwed systems and aggressive chloride-bearing process environments where crevice corrosion at thread interfaces is a primary concern.

ASTM A182 F53UNS S32750UNS S32760

Quality & Compliance

Standards, Testing & Documentation

Applicable Standards

Standard	Description
ASME B16.11	Forged Fittings, Socket-Welding & Threaded — dimensional standard
ASTM A182	Material specification for forged alloy and stainless steel fittings
ASME B1.20.1	NPT threads — form, dimensions and tolerances for both ends
BS EN 10226	BSP pipe threads — available on request
MSS SP-25	Standard marking for valves, fittings and flanges
EN 10204	3.1 MTC standard; 3.2 with TPI on request

Quality Tests Performed

Test	Method / Scope
Chemical Analysis	OES per ASTM A182 for each heat of material
Mechanical Testing	Tensile, yield, elongation and Charpy impact where specified
Hardness Testing	Brinell or Vickers per ASTM A182 requirements
Thread Gauging	100% go/no-go on both male OD and female ID threads per ASME B1.20.1
PMI	100% XRF Positive Material Identification on request
Dimensional Inspection	100% per ASME B16.11 — length, hex width, concentricity of both threads

Applications

Where Threaded Hex Bushings Are Used

01

In-Line Bore Reduction

Reducing bore from a larger female fitting outlet to a smaller threaded pipe or tubing in a single compact fitting, replacing a separate reducing coupling arrangement and eliminating one joint from the piping assembly.

02

Instrument Connection Adapters

Adapting large-bore female threaded fittings or valve bodies to smaller-bore instrument connection sizes, allowing standard instrument accessories with smaller NPT connections to be installed directly without additional nipples or adaptors.

03

Chemical Injection Skids

Connecting smaller-bore injection quill tubing to larger-bore pump outlet connections and distribution manifold ports using hex bushings in Stainless Steel or Duplex Steel for chemical resistance throughout the dosing skid pipework.

04

Manifold Port Reduction

Reducing spare female ports on multi-port manifolds and distribution blocks to a smaller standard pipe size for connection to smaller-bore branch lines, instrument connections and sampling ports using a single compact bushing fitting.

Threaded Fittings Range

Forged Threaded Hex Reducing Bushing

Forged Threaded Hex Reducing Bushing

Threaded Hex Bushing — ASME B16.11 Size Combinations

Material Grades for Threaded Hex Bushings

Stainless Steel 304 / 316

Duplex Steel

Super Duplex Steel

Standards, Testing & Documentation

Applicable Standards

Quality Tests Performed

Where Threaded Hex Bushings Are Used

In-Line Bore Reduction

Instrument Connection Adapters

Chemical Injection Skids

Manifold Port Reduction

Other Forged Threaded Fittings

Threaded Plug

Threaded Cap

Threaded Reducing Coupling

Threaded Hex Nipple

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