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IS 11931:1987 is the Indian Standard (BIS) for sewer cleaning metal rods. This standard specifies the requirements for materials, dimensions, construction, workmanship, finish, and testing of metal rods used for cleaning sewers and drains. It covers two standard diameters and ensures the rods have adequate strength and flexibility for manual cleaning operations.
! The referenced material standard IS 226 has been superseded by IS 2062. Ensure the steel grade used is equivalent, typically E250 (Fe 410W) Grade A.
! The design and quality of the couplings between rod sections are critical for performance and durability, though not exhaustively detailed in the code. This is a common point of failure.
! Proper galvanization or coating as per Clause 5.3 is essential to prevent rapid corrosion in the harsh sewer environment.
BS 3341:1961BSI (British Standards Institution), United Kingdom
HighWithdrawn
Specification for drain and sewer cleaning rods of cane or flexible steel, and ancillary equipment
Directly covers the specification for flexible steel sewer cleaning rods with similar coupling types (screw and lockfast).
DIN 19549:1989-11DIN (Deutsches Institut für Normung), Germany
LowCurrent
Drain and sewer systems outside buildings; cleaning of drains and sewers
Specifies the process and requirements for cleaning sewers, the application where these rods are used, but not the tool itself.
Key Differences
≠IS 11931:1987 specifies only metal (high-tensile steel) rods, whereas the closest equivalent, BS 3341:1961, also included specifications for rods made of cane.
≠The Indian Standard uses metric units exclusively (e.g., 20 mm diameter, 60 N·m torque), while older international standards like BS 3341 used imperial units (e.g., 7/8 inch diameter, lbf·ft torque).
≠IS 11931:1987 specifies a nominal rod diameter of 20 mm, while BS 3341:1961 specified a 7/8 inch (approx. 22.2 mm) diameter for steel rods, resulting in a slight dimensional incompatibility.
≠The standard rod lengths differ; IS 11931 specifies 1 m, 1.2 m, and 1.5 m lengths, while BS 3341 specified a standard length of 3 ft (approx. 0.91 m).
Key Similarities
≈Both IS 11931 and BS 3341 specify the two most common types of couplings: the standard screw type and the more secure 'Lockfast' type.
≈The primary materials of construction are similar, with both standards specifying malleable cast iron for the couplings and flexible, high-strength steel for the rods.
≈Both standards mandate performance tests to ensure reliability, including a torsion test for the couplings and a flexibility test for the rod itself.
≈A requirement for a protective galvanized coating on both the steel rods and the iron couplings is a common feature to prevent corrosion.
Parameter Comparison
Parameter
IS Value
International
Source
Rod Material
High tensile steel wire
Flexible steel (or cane)
BS 3341:1961
Coupling Material
Malleable cast iron conforming to IS 2108
Malleable cast iron
BS 3341:1961
Nominal Rod Diameter
20 mm
7/8 inch (≈22.2 mm) for steel rods
BS 3341:1961
Standard Rod Lengths
1 m, 1.2 m, 1.5 m
3 ft (≈0.91 m)
BS 3341:1961
Coupling Types
Screw type and Lockfast type
Ordinary screw type and Lockfast type
BS 3341:1961
Torsion Test (Coupling)
Must withstand a torque of 60 N·m
Must withstand a torque of 40 lbf·ft (≈54.2 N·m)
BS 3341:1961
Protective Coating
Galvanized
Galvanized
BS 3341:1961
⚠ Verify details from original standards before use
Key Values5
Quick Reference Values
Nominal diameter of rods12 mm or 16 mm
Nominal length of each rod section1 m
Tolerance on diameter±0.4 mm
Tolerance on length±10 mm
Minimum tensile strength of steel410 MPa (as per IS 226)
Tables & Referenced Sections
Key Tables
Table 1 - Dimensions of Metal Rods for Sewer Cleaning
What are the standard diameters for sewer cleaning rods as per IS 11931?+
The standard specifies nominal diameters of 12 mm and 16 mm (Clause 4.1).
What is the material specified for these rods?+
The rods shall be made from steel conforming to IS 226 (now superseded by IS 2062) or other equivalent standards (Clause 3.1).
What is the standard length of one rod section?+
Each rod section should have a nominal length of 1 meter (Clause 4.2).
What is the flexibility test requirement for these rods?+
The rod must be capable of being bent cold through 180 degrees around a former of diameter equal to the rod's nominal diameter without showing any sign of fracture or cracks (Clause 7.2).