SDR 35 pipe: sizes, specs and how it compares to schedule 40

SDR-35 pipe: what we stock

SDR 35 pipe sizes and dimensions

SDR 35 has the same outside diameter as ASTM D2729 pipe but a thicker wall. The wall grows with the diameter, so every size has the same ratio of diameter to wall and the same stiffness: 46 psi, which is why the pipe is also called PS46.

Dimensions from JM Eagle's ASTM D3034 SDR 35 submittal. Other makers' figures can differ slightly; check the data sheet for the pipe on your order.

How does SDR 35 compare with schedule 40, D2729 and triplewall?

All four are pipe we stock, and they don't do the same job. SDR 35 and D2729 share a sewer-size outside diameter. Schedule 40 uses iron pipe size, which is bigger. Triplewall is a lighter HDPE drain pipe with a three-layer wall. It is a different pipe from SDR 35, not a version of it.

PVC makers warn never to test or run compressed air or gas through PVC pipe. Pressure-test with water only, per the maker's instructions.

Solvent weld or gasketed SDR 35

Solvent weld SDR 35 comes in 10' lengths with a bell end. Joints are glued with primer and PVC cement, which gives a rigid, leak-free joint. We stock it in 4" and 6", solid or perforated, which covers house sewers, septic tank lines and perforated leach or drain lines.

Gasketed SDR 35 has an integral bell with a rubber gasket, made to ASTM F477 and D3212. It pushes together, needs no glue, and comes in a 14' laying length. We stock it from 4" to 15" for sewer mains, storm runs and longer gravity lines.

How do you connect SDR 35 to schedule 40?

A 4" SDR 35 pipe is 4.215" outside. A 4" schedule 40 pipe is 4.500". The two won't fit the same hub. Join them with an adapter fitting or a flexible coupling sized for both.

Fernco couplings seal on the outside diameter and join different pipe sizes and materials. Their standard couplings are made for drain, waste, vent and sewer service, not pressure lines. We stock Fernco couplings in 4", 6" and 8".

What to order with SDR 35

• Fittings to match the joint: SDR solvent weld 3" to 6" or SDR gasketed 4" to 8"
• PVC primer and cleaner and PVC cement, in pints and quarts, for solvent weld joints
• Fernco couplings to tie into schedule 40, cast iron or clay
• Septic tanks, distribution boxes and effluent filters for septic lines
• Detectable sewer tape for the trench

Questions about SDR-35 pipe

What does SDR 35 mean in pipe?

SDR stands for standard dimension ratio: the pipe's outside diameter divided by its minimum wall thickness. For 4" SDR 35, 4.215" divided by 0.120" is about 35. The higher the number, the thinner the wall. SDR 35 PVC is made to ASTM D3034 for gravity sewer and drain lines.

Is SDR 35 stronger than schedule 40?

Schedule 40 has the thicker wall: 0.237" at 4", against 0.120" for SDR 35. Schedule 40 made to ASTM D1785 carries a pressure rating. SDR 35 is gravity pipe with a 46 psi stiffness rating for buried sewer lines. Use the pipe the plans or local code call for.

Can you connect SDR 35 to schedule 40?

Yes, with an adapter fitting or a flexible coupling. The outside diameters differ: 4.215" for 4" SDR 35 and 4.500" for 4" schedule 40. Fernco couplings seal on the outside diameter and join different pipe sizes and materials. Yankocy stocks Fernco couplings in 4", 6" and 8".

How many lengths of SDR 35 are on a skid?

Typically 90 lengths of 4" SDR 35 or 40 lengths of 6" per skid. Triplewall, which is HDPE drain pipe rather than SDR 35, runs 90 lengths per skid. Yankocy sells pipe wholesale by the skid to yards and delivers it on our own trucks from Monroe, CT.

Do you glue SDR 35 pipe?

Solvent weld SDR 35 is glued with PVC primer and cement at the bell. Gasketed SDR 35 is not glued. It has a rubber gasket in the bell and pushes together. Yankocy stocks solvent weld 4" and 6" x 10' and gasketed 4" to 15" x 14', plus primer and cement.

What is ASTM D2729 pipe?

ASTM D2729 is thin-wall PVC sewer and drain pipe for non-pressure work such as footing drains, leaders and yard drainage. It is not rated for pressure. Perforated D2729 has rows of 1/2" holes every 5". Yankocy stocks it in 3", 4" and 6" solid and 4" and 6" perforated.

Last updated November 2, 2026

Yankocy sells SDR 35, triplewall, D2729 and schedule 40 pipe wholesale to lumber, mason and landscape yards. Buying for your own home? Your local lumber or mason yard can order it for you.

SDR-35 pipe data sheets and sources

• JM Eagle: Gravity Sewer submittal, ASTM D3034 SDR 35
• JM Eagle: Solvent Weld Sewer & Drain
• Westlake Pipe & Fittings: ASTM D2729 PVC Sewer & Drain Pipe spec
• Charlotte Pipe: PVC D 2729 Sewer and Drain submittal
• Charlotte Pipe: PVC Schedule 40 DWV submittal
• Charlotte Pipe: Pressure dimensional catalog (schedule 40 D1785)
• ADS: 3000 TripleWall pipe sell sheet
• Fernco: Standard flexible couplings

Related to SDR-35 pipe

• Septic tanks
• Septic distribution boxes
• NDS channel drains
• NDS Flo-Well dry well
• All drainage & septic