Name: Forged Threaded Hex Plug
Brand: Cunimet Alloy International

Product Overview

Forged Threaded Hex Plug

The Forged Threaded Hex Plug is a solid male-threaded closure fitting used to blank off the female-threaded outlet of a pipe fitting — such as an unused outlet of a tee, cross, coupling or valve body. The male NPT external threads on the plug body engage the female NPT threads of the fitting outlet, and the solid forged body blocks the bore completely. The hex head above the thread engagement zone provides spanner flats for wrench tightening and removal.

Unlike a threaded cap (which screws over a male pipe end), the hex plug screws into a female fitting and sits flush or slightly proud of the fitting face. This makes the plug the standard solution for blanking unused ports on manifolds, tees, crosses and instrument connections throughout threaded piping systems. Cunimet Alloy International manufactures hex plugs through closed-die forging for a dense, uniform body. All NPT threads are CNC-machined to ASME B1.20.1 tolerances and 100% go/no-go gauge inspected.

ASME B16.11 ASME B1.20.1 (NPT) 1/8" to 4" NPS 2000# • 3000# • 6000# Male NPT + Hex Head

Request a Quote

ASMEStandardB16.11

M.NPTThread TypeMale + Hex Head

1/8–4"Size RangeNPS

2000#Min. ClassAlso 3000# & 6000#

3Material GradesSS / Duplex / S.Duplex

Technical Dimensions

Threaded Hex Plug — ASME B16.11 Dimensions

“L” = Overall length from the face of the hex head to the end of the male NPT thread. “W” = Hex width across flats. Thread form per ASME B1.20.1 (NPT). All dimensions in millimetres.

NPS	Nominal Thread O.D. (mm)	Length “L” (mm)			Hex Width “W” (mm)			TPI
NPS	Nominal Thread O.D. (mm)	2000#	3000#	6000#	2000#	3000#	6000#	TPI
1/8"	10.3	13	16	16	13	13	13	27
1/4"	13.7	16	19	19	17	17	17	18
3/8"	17.1	19	22	22	22	22	22	18
1/2"	21.3	22	25	29	27	27	27	14
3/4"	26.7	25	29	35	34	34	34	14
1"	33.4	29	35	44	41	41	41	11.5
1-1/4"	42.2	35	41	51	51	51	51	11.5
1-1/2"	48.3	38	44	57	57	57	57	11.5
2"	60.3	44	51	67	68	68	68	11.5
2-1/2"	73.0	51	60	79	83	83	83	8
3"	88.9	57	67	89	95	95	95	8
4"	114.3	70	83	111	117	117	117	8

Dimensions are nominal per ASME B16.11 latest edition. BSP plugs to BS EN 10226 available on request. All dimensions in millimetres.

Available Materials

Material Grades for Threaded Hex Plugs

Grade 01

Stainless Steel 304 / 316

Austenitic stainless steel hex plugs for blanking female ports on tees, crosses, manifolds and valve bodies in chemical, pharmaceutical, food and water treatment screwed piping. SS 316 preferred for chloride and marine environments.

ASTM A182 F304ASTM A182 F316ASME B16.11

Grade 02

Duplex Steel

High-strength duplex alloy hex plugs for offshore instrument manifold ports, chemical injection system outlet closures and process valve body blanking where chloride stress corrosion cracking resistance is required at every fitting closure point.

ASTM A182 F51UNS S31803UNS S32205

Grade 03

Super Duplex Steel

Premium super duplex hex plugs with PREN greater than 40 for blanking female ports on seawater service fittings, offshore topsides manifolds and subsea equipment where maximum pitting and corrosion resistance at all closure fittings is specified.

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 Pipe Threads — thread form, dimensions and tolerances
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% male NPT go/no-go gauge per ASME B1.20.1
PMI	100% XRF Positive Material Identification on request
Dimensional Inspection	100% per ASME B16.11 — length, hex width, thread form

Applications

Where Threaded Hex Plugs Are Used

01

Unused Fitting Port Closure

Blanking off unused outlets on threaded tees, crosses, manifolds and multi-port valve bodies where one or more ports are not connected to the process during normal operation but must remain pressure-tight.

02

Instrument Manifold Blanks

Plugging spare female NPT ports on instrument manifold blocks, gauge valves and sampling panels to prevent leakage at unused connection points while maintaining the ability to connect instruments in the future.

03

Drain & Vent Point Sealing

Sealing female drain and vent threaded connections when not in use, providing a removable pressure-tight blank that can be quickly removed for draining or venting and reinstalled without special tools or replacement sealing materials.

04

Pressure Testing

Temporary closure of female threaded test ports, drain connections and vent points during hydrostatic and pneumatic pressure testing of process piping systems and pressure vessels, removed after testing is complete.

Threaded Fittings Range

Forged Threaded Hex Plug

Forged Threaded Hex Plug

Threaded Hex Plug — ASME B16.11 Dimensions

Material Grades for Threaded Hex Plugs

Stainless Steel 304 / 316

Duplex Steel

Super Duplex Steel

Standards, Testing & Documentation

Applicable Standards

Quality Tests Performed

Where Threaded Hex Plugs Are Used

Unused Fitting Port Closure

Instrument Manifold Blanks

Drain & Vent Point Sealing

Pressure Testing

Other Forged Threaded Fittings

Threaded Cap

Threaded Bushing

Threaded Full Coupling

Threaded Hex Nipple

Get a Quote for Threaded Hex Plugs