Shiv Shakti Machine ToolsFlange manufacturer and trader, home

Lap joint flanges

A loose flange used with a stub end. It turns freely for easy bolt-hole alignment, which suits lines that are often taken apart. [CONFIRM: this type is made]

3D model

Showing 6" Class 150, RF, ASME B16.5 Change size

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Key to the letters

O
Flange diameter
Tf
Flange thickness
X
Hub diameter
B
Bore
B1
Bore
Y
Length through hub
r
Radius
W
Bolt circle (PCD)
d
Bolt hole diameter
n
Number of holes

Values in mm, from the table below.

Specification

Type
Lap joint (LJ)
Model shown
6" Class 150, RF, ASME B16.5
Units
mm, inches for ASME sizes
Sizes
½" to 24" NB (DN 15 to DN 600). Dimension tables: ½" to 24" to ASME B16.5. [CONFIRM: sizes]
Ratings
ASME Class 150, 300, 600, 900, 1500 and 2500. PN 6 to PN 100. JIS 5K to 20K. [CONFIRM: ratings]
Facings
Raised face (RF), flat face (FF), ring type joint (RTJ), tongue and groove (T&G), and male and female (M&F). Standard serrated finish, 3.2 to 6.3 µm Ra (125 to 250 µin). Smooth finish on request. [CONFIRM: facings]
Standards
ASME B16.5 (NPS ½" to 24"), EN 1092-1 (DN 15 to DN 600), DIN, BS 4504, BS 10 (Tables D, E, F and H), JIS B2220, IS 6392. [CONFIRM: standards for lap joint]
Materials
Carbon steel A105 and A105N. Low-temperature carbon steel LF2 Class 1 and LF3. High-yield carbon steel F42, F46, F52, F56, F60, F65 and F70. Alloy steel F1, F5, F9, F11, F12, F22 and F91. EN and DIN grades P245GH and P250GH (C22.8). [CONFIRM: grades]
Finishes
Rust-preventive oil and black anti-rust paint. [CONFIRM: finishes]
Documents and inspection
EN 10204 3.1 material test certificate. Dimensional inspection report. Third-party inspection on request, for example BV, SGS, TÜV, Lloyd’s Register, DNV.

The marking, explained

Every flange is stamped on its rim, so it can be traced to its heat and its material certificate. Choose any part of the stamp to see what it means.

150Class

Pressure class 150 to ASME B16.5. The pressure it can hold at a given temperature depends on the material.

HT 24A117 is a sample heat number. The stamp follows MSS SP-25.

[CONFIRM: exact stamp format and the mark we stamp]

Dimensions

Lap joint, ASME B16.5, Class 150. Choose a size to see it in the viewer.

Units

Swipe the table sideways for every column. Choose a size to show it in the viewer.

Lap joint flanges, ASME B16.5 Class 150, dimensions in mm
NPSSizeDNNominal sizeOFlange diameterTfFlange thicknessXHub diameterBBoreB1BoreYLength through hubrRadiusWBolt circle (PCD)dBolt hole diameternNumber of holeskgWeight, approx.Enquiry list
159011.23022.915.816360.315.940.4
2010012.73828.220.916369.915.940.7
2511014.34934.926.617379.415.940.8
3211515.95943.735.121588.915.941.1
4012517.5655040.922698.415.941.4
5015019.17862.552.5258120.71942.2
6518022.39075.462.7298139.71943.6
8019023.910891.477.93010152.41944.1
9021523.9122104.190.13210177.81985.2
10023023.9135116.8102.33311190.51985.6
12525523.9164144.4128.23611215.922.286.3
15028025.4192171.4154.14013241.322.287.5In the viewer
20034528.6246222.2202.74413298.522.2812.6
25040530.2305277.4254.6491336225.41218.5
30048531.8365328.2304.85613431.825.41228
35053535400360.2336.57913476.328.61235
40059536.6457411.2387.38713539.828.61645
45063539.7505462.3438.19713577.931.71650
50070042.9559514.4488.91031363531.72064
60081547.7663616590.511113749.334.92089

Dimensions in mm, for reference. Tolerances and full requirements as per the applicable standard. Confirm against your specification before ordering.

Source: Shiv Shakti Machine Tools Flange Catalogue, edition 2026 (draft), page 9, weights page 15. “–” means the catalogue lists no value.

[CONFIRM: table checked and signed off by the owners (unverified)]

Where it’s used

Lines that need frequent dismantling.

Industries: oil and gas, refining and petrochemical, power generation, water and wastewater, chemical and fertiliser, and general fabrication.

By material

Carbon steel
General service, from ambient to elevated temperatures
Low-temperature carbon steel
Low-temperature service. LF2 Class 1 is impact-tested at −46 °C.
High-yield carbon steel
High-pressure transmission pipelines, matched to API 5L line pipe grades
Alloy steel
High-temperature service in power and refining
EN and DIN grades
Flanges to EN 1092-1 and DIN

Grades and standards

Lap jointASME B16.5

6" Class 150 lap joint

Lap joint