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Stub End Lap Joint


Bu-LOK is a leading India based manufacturer, exporter and supplier of high quality, high performance stub end (lap joint) fittings in all major grades and dimensions. Stub ends can be supplied in standard and non-standard ANSI dimensions. Bu-LOK offers ex-stock supply of stainless steel stub ends, carbon steel stub ends, alloy steel stub ends and nickel alloy stub ends. Special length stub ends or lap joints can also be offered on demand.

Stub ends are fittings used in place of welded flanges where rotating back up flanges are desired. They are mainly used with standard Lap Joint Flanges.

We manufacture and supply stub ends in various grades such as 304/304L, 304H, 316/316L, 321, 347, Duplex steel, 904L, Alloy 20, 317L and 310S. We supply stainless steel stub ends across various industry verticals such as power generation, oil and gas, petrochemical, chemical, fabrication and engineering, waste water treatment, and pharmaceutical industry.


Stub End/Lap Joint Production Range

Outside Diameter: 1/2″ – 24″
Type: Long/Short Stub Ends
Wall Thickness: 2mm – 100 mm / SCH5, SCH10, SCH20, SCH30, SCH40, STD, SCH80, XS, SCH60, SCH120, SCH140, SCH160, XXS
Production Grades: Stainless Steel, Alloy Steel, Duplex, Nickel Alloys, Low temperature Steel, Carbon Steel, Cupro Nickel
Value Added Services: Hot Dipped Galvanizing, Epoxy & FBE Coating, Electro Polish, Sand Blasting, Threading, Soldering

Manufacturing Standards

ASME: ANSI B16.9, ANSI B16.28, MSS-SP-43
DIN: DIN2605, DIN2615, DIN2616, DIN2617, DIN28011
EN: EN10253-1, EN10253-2

ASTM A403 – ASME SA403 Standard Specification for Wrought Austenitic Stainless Steel Piping Fittings
ASME B16.9 Factory-Made Wrought Fittings Buttwelding
ASME B16.25 Buttwelding Ends ASME B16.28 – Wrought Steel Short Radius Elbows and Buttwelding Returns
MSS SP-43 Wrought and Fabricated Butt-Welding Fittings for Low Pressure, Corrosion Resistant Applications

Stub Ends Material Grades

Stainless Steel Stub End ASTM A403 WP Gr. 304, 304H, 309, 310, 316, 316L, 317L, 321, 347, 904L
Carbon Steel Stub End ASTM A 234 WPB , WPBW, WPHY 42, WPHY 46, WPHY 52, WPH 60, WPHY 65 & WPHY 70.
Low Temperature Carbon Steel Stub End ASTM A420 WPL3, A420 WPL6
Alloy Steel Stub End ASTM / ASME A/SA 234 Gr. WP 1, WP 5, WP 9, WP 11, WP 12, WP 22, WP 91
Duplex Stub End ASTM A 815, ASME SA 815 UNS NO S31803, S32205. Werkstoff No. 1.4462
Nickel Alloy Stub End ASTM / ASME SB 336 UNS 2200 ( NICKEL 200 ), UNS 2201 (NICKEL 201 ), UNS 4400 (MONEL 400 ), UNS 8020 ( ALLOY 20 / 20 CB 3, UNS 8825 INCONEL (825), UNS 6600 (INCONEL 600 ), UNS 6601 ( INCONEL 601 ), UNS 6625 (INCONEL 625), UNS 10276 ( HASTELLOY C 276 )

Marking & Packing

Products are packaged to ensure that there is no damage during transit. In case of exports, standard export packaging is done in wooden cases. All elbow fittings are marked with Grade, Lot No, Size, Degree and our trade mark. On special requests we can also, make custom marking on our products.

Quality Assurance

At Bu-LOK , all fittings and flanges are subject to strict inspection at each stage of the production process, from starting material purchasing to product dispatch. They are visually examined for conformity to ASTM, ASME, MSS, DIN, EN, and JIS codes and standards. Upon request, official certified Inspection Agencies can be called in to witness the material reports, dimensions and quality conformity of products.