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Seamless Carbon Steel Tubing, 0.38 Inch OD, 0.07 Inch Thick, 0.25 Inch ID

Description & Features

Manufactured by Marmon/Keystone, this seamless carbon steel tubing is designed with robust specifications suitable for a variety of industrial applications. With an outside diameter of 0.38 inches, an inside diameter of 0.25 inches, and a wall thickness of 0.07 inches, this high-quality tubing is engineered for demanding environments.

Rated to a maximum working pressure of 3178 psi with a burst pressure of 19067 psi, the tubing adheres to SAE J524 standards, ensuring reliability and safety. Featuring a tensile strength of 55,000 psi, it is ideal for applications where precise bending and flaring are required.

The tubing's inner diameter of 0.245 inches and inside area of 0.0471 make it well-suited for systems requiring specific flow rates, with a rated flow of 2.6. Its adherence to the conservative Barlow formula solidifies its pressure rating, confirming its safety and durability.

When selecting this tubing, please review safety and application information to ensure proper use. This seamless carbon steel piece is precisely crafted, making it an excellent choice for industrial tubing needs.

Supplier Part Number: 3/8.065

MPN: {{ecc_mpn}}

Specifications

Burst Pressure 19067	Brand Marmon/Keystone	Brand Marmon - Keystone	Pack Size 12.00	UOM FT	I.D. 0.245 in	Inside Area 0.05	Maximum Working Pressure 3178	O.D. 0.375 in	Rated Flow 2.60	Safety Factor 6:1	Supplier Part Number 3/8.065	Wall Thickness 0.07	Alternate Part Numbers Alternate Part Number C1BK90, Alternate Part Number MI-08754326, Alternate Part Number MINO-01965X80002	Product Weight 0.13 lbs

Similar Products

Model Number	O.D.	Wall Thickness	I.D.	Inside Area	Rated Flow	Maximum Working Pressure	Burst Pressure	Safety Factor
1/2.049 Seamless Carbon Steel Tubing	0.5 in	0.049	0.402 in	0.1269	6	1797	10780	6:1
1/2.065 Seamless Carbon Steel Tubing	0.5 in	0.065	0.37 in	0.1075	4.9	2383	14300	6:1
1/4.049 Seamless Carbon Steel Tubing	0.25 in	0.049	0.152 in	0.0181	0.8	3593	21560	6:1
3/8.049 Seamless Carbon Steel Tubing	0.375 in	0.049	0.277 in	0.0602	2.8	2396	14373	6:1
3/8.065 Seamless Carbon Steel Tubing	0.375 in	0.065	0.245 in	0.0471	2.6	3178	19067	6:1
5/8.095 Seamless Carbon Steel Tubing	0.63 in	0.095	0.435 in	0.1485	6.9	2787	16720	6:1
1-1/4.095 Seamless Carbon Steel Tubing	1.25 in	0.095	1.06 in	0.882	41	1393	8360	6:1
1-1/4.120 Seamless Carbon Steel Tubing	1.25 in	0.12	1.01 in	0.8008	36.7	1760	10560	6:1
1.065 Seamless Carbon Steel Tubing	1 in	0.065	0.87 in	0.5942	28.1	1192	7150	6:1
1.120 Seamless Carbon Steel Tubing	1 in	0.12	0.76 in	0.4534	20.7	2200	13200	6:1
1/2.083 Seamless Carbon Steel Tubing	0.5 in	0.083	0.334 in	0.0876	4	3043	18260	6:1
3/16.035 Seamless Carbon Steel Tubing	0.1875 in	0.035	0.1175 in	0.0108	0.4	3422	20533	6:1
3/4.049 Seamless Carbon Steel Tubing	0.75 in	0.049	0.652 in	0.3337	15.4	1198	7187	6:1
3/4.065 Seamless Carbon Steel Tubing	0.75 in	0.065	0.62 in	0.3018	12	1589	9533	6:1
3/4.095 Seamless Carbon Steel Tubing	0.75 in	0.095	0.56 in	0.2462	11	2322	13933	6:1
3/4.109 Seamless Carbon Steel Tubing	0.75 in	0.109	0.532 in	0.2222	10.6	2664	15987	6:1
5/8.065 Seamless Carbon Steel Tubing	0.63 in	0.065	0.495 in	0.1923	9	1907	11440	6:1

Product Questions & Answers (3)

Question by: Norm W on Dec 12, 2025, 12:43 PM

got a piece of 3/8 tubing here, is this one actually 3/8 OD and what’s the inside size on it?

Answer by: Customer Support on Dec 14, 2025, 7:35 AM

For sizing, the outside diameter is 0.375 inch (3/8), with a 0.065 inch wall. That puts the inside diameter at about 0.245 inch (roughly 1/4), so it is a 3/8 OD by 0.065 wall tube.

Question by: Neil C on Jun 26, 2025, 9:35 AM

tubing says it's rated to 3178 psi but I've heard that number can change depending on how much shock is in the system. is that right?

Answer by: Customer Support on Jun 27, 2025, 2:32 PM

Your instinct is correct. That 3178 psi working pressure is based on a 6:1 safety factor, which is the standard applied when hydraulic shock and mechanical strain are considered considerable. If conditions in your system are more severe than that, an 8:1 safety factor should be used instead, which brings the working pressure down further. On the flip side, if shock and strain in your application are minimal, a 4:1 factor can be carefully considered, which allows for higher working pressures. The burst pressure on this tubing is 19,067 psi, and the working pressure figures are derived from that using the Barlow formula.

Question by: Lyle H on Feb 15, 2026, 8:28 AM

got a tubing bender set up for 3/8 line, is this the right stuff or am i gonna be fighting it?

Answer by: Customer Support on Feb 16, 2026, 3:25 PM

Made to SAE J524, the tube is annealed specifically for bending and flaring, so it is a good match for typical 3/8 inch OD bending setups. The outside diameter is 0.375 inch with a 0.065 inch wall and about a 0.245 inch inside diameter.