High-Quality T91 Carbon Alloy Steel Pipe for Packaging

Product Description

Product Description

ONE MATERIAL FAMILY

What Is Chromoly Steel Tubing?

Chromoly steel tubing refers to a family of low-alloy steel tubes alloyed primarily with chromium and molybdenum.

Compared with conventional carbon steel tubing, a properly selected Cr-Mo grade and delivery condition can provide a useful combination of strength, toughness, hardenability, fatigue resistance and heat-treatment response.

Different grades are selected for different strength levels, fabrication routes, heat-treatment requirements and end-use applications.

Start With the Material Grade

SAE 4130, Chinese 30CrMo, European 25CrMo4 and Japanese SCM430 are commonly compared because they belong to a similar low-carbon Cr-Mo family. They are not automatically interchangeable.

≡ 4130-type grades support a practical balance of strength, formability and weldability.

≡ 4140, 42CrMo and 42CrMo4 families are commonly selected for quenched-and-tempered mechanical parts.

≡ The purchase specification and material certificate control the delivered grade.

Global Chromoly Steel Grades
Carbon band	USA SAE / AISI	EN / DIN	JIS	GB	Typical selection direction
Lower	4115	--	SCM415	15CrMo	Carburized components and tough-core parts
Lower	4120	--	SCM420	20CrMo	Machined components requiring surface hardening
Medium	4130	25CrMo4	SCM430	30CrMo	Welded, formed and structural tube applications
Medium	4135	34CrMo4	SCM435	35CrMo	Higher hardenability mechanical components
Higher	4140 / 4142	42CrMo4	SCM440	42CrMo	Quenched-and-tempered, heavily loaded parts
Similar or commonly cross-referenced grade families only. Chemical composition, mechanical properties, hardenability, heat treatment and tube delivery requirements shall be confirmed against the specified material and tube standards. These entries are not automatic substitutes.

Specification

Parameter	Product-page value	Order confirmation
Product	Chromium-molybdenum seamless round steel tube	Mechanical tube supply
Core grades	SAE 41XX; 25CrMo4/34CrMo4/42CrMo4; SCM series;CrMo grades under GB references	Other Cr-Mo grades by review
Tube standards	ASTM A519/A519M, GB/T 8162, GB3639,GB3077,EN10305-1,EN 10297-1, JIS G 3441 or customer specification	Confirm standard and edition
Outside diameter	15-70 mm	Confirm OD tolerance
Wall thickness	1-14 mm	Confirm wall tolerance
Length	3 m, 6 m, 6.1 m or custom cut length	Confirm length and tolerance
Delivery condition	Cold-finished, stress-relieved, annealed, normalized or heat treated as specified	Condition is grade dependent
Surface	Bare, black, bright, lightly oiled or phosphate coated	Confirm corrosion protection
Inspection	Material identification, OD, wall, length, straightness and surface	Mechanical, hardness or NDT by order
Processing	Cutting, chamfering, drilling, notching and CNC machining by drawing review	Drawing required
Certificate	Material certificate and heat-lot traceability by order	State document requirement
Packing	Protected bundles, end protection and export packing	Confirm packing method

Applications

One Alloy Family, Multiple Mechanical Uses

Motorsport Structures                            Automotive Components                                 Hollow Shafts                                  Industrial Machinery        

Roll cages, tubular chassis,                       Stabilizer bars, suspension links,               Machined shafts, sleeves, annular       High-load mechanical tubes, bush

reinforcement bars and vehicle             steering and transmission members.            parts and weight-reduced                   housings and custom tubular parts.

frames.                                                                                                                                    components.

Available Delivery Conditions

Prepared for Cutting, Bending and Machining

Availability depends on steel grade, tube size, required properties and the specified standard.Finished tube appearance varies by route, heat treatment and surface requirement.

≡ HF  Hot finished                             General seamless tube condition

≡  CD  Cold drawn                             Precision cold-worked route

≡  A    Annealed                                 Ductility and machining review

≡ SR  Stress relieved                       Reduced cold-work residual stress

≡ N   Normalized                              Balanced structure and properties

≡ Q&T Quenched and tempered   For applicable higher-strength grades

Tube condition can be selected around the buyer's forming, machining and joining route. Higher-carbon grades require tighter control of welding and heat treatment than 4130-type material.

≡ Fixed-length cutting and end preparation
≡ Chamfering, drilling and CNC tube machining by drawing
≡ Notching and bending feasibility review
≡ Stress-relieved, annealed, normalized or quenched-and-tempered condition by specification

Manufacturing Process

Material Review

Hot Piercing & Tube Forming

Cold Drawing

Grade verification and heat-number traceability

Two-roll rotary piercing forms the seamless hollow shell

Long-bed axial drawing controls dimensions and surface

Heat Treatment

Straightening & Cutting

Inspection & Packing

Order-specific delivery condition

Straightness control and square ends

Final checks and protected shipment

Grade Identity and Order Traceability

For Cr-Mo steel tube, material identity is as important as dimensional accuracy. Each quotation should define the required grade, condition and certificate.

≡ Heat-lot and material-grade identification

≡ OD, wall thickness, length and straightness inspection

≡ Surface and end-condition verification

≡ Additional mechanical, hardness or NDT requirements by order

≡Protected export packing and marking review

Information Required for Quotation

Send the complete tube requirement to avoid grade or condition mismatch.

≡ Grade and standard                              Example: SAE 4130 to ASTM A519/A519M

≡ OD and wall                                            Within 15-70 mm OD and 1-14 mm wall

≡ Condition                                                Cold-finished, SR, annealed, normalized or Q&T

≡ Tolerance and length                            Standard tolerance or approved drawing

≡ Tests and certificate                             Mechanical, hardness, NDT and MTC needs

≡ Quantity and processing                      Batch quantity, cutting or machining drawing

FAQ

Q:Is 4130 the same as 30CrMo or 25CrMo4?

A:They are commonly compared low-carbon Cr-Mo grades, but their chemistry limits and product standards are not identical. Confirm the required standard before ordering.

Q:Can 4140 be welded like 4130?

A:4140-type grades have higher carbon and hardenability. The buyer must establish a suitable welding, preheat and post-weld procedure for the component and delivery condition.

Q:What is the available size range?

A:The confirmed factory range is 15-70 mm outside diameter and 1-14 mm wall thickness. Specific combinations are reviewed by grade, tolerance, condition and quantity.

Q:Can different national grades be substituted?

A:Only after chemistry, hardenability, mechanical properties, heat treatment, dimensions and the applicable tube standard have been reviewed and accepted.

Q:Do you supply cut or machined chromoly tube parts?

A:Cutting, chamfering, drilling, notching and CNC machining can be reviewed from the drawing and batch requirement.

Q:Are T11 and T22 the same product as 4130 and 4140 tube?

A:No. T11/T22 and their regional counterparts are pressure and high-temperature grades under different standards. They are listed only to explain the wider Cr-Mo tube market.