42CrMo4 4140 Alloy Steel Hollow Bar

4140 / 42CrMo4 Alloy Steel Hollow Bar – Precision Machined & Custom Cylinder Components

1. Product Overview

4140 / 42CrMo4 hollow bar is a thick-wall seamless alloy steel tube, ideal for precision machining of hydraulic cylinders, press components, and heavy-duty shafts.

At Chengxin, we offer:

• Cold drawn hollow bars

• Hot rolled + deep hole bored bars

• Hot forged + deep hole drilled bars

Our AISI 4140 hollow bar solutions meet stringent tolerance and mechanical requirements for industrial and hydraulic applications.

2. Commodity Name

AISI 4140 / 42CrMo4 Alloy Steel Hollow Bar

3. Available Steel Grades

• ASTM A519: 1020, 1026, 1045, 4130, 4140, 4145, 4340, 8620

• DIN 2391-2: ST45, ST52

• EN 10305-1: E235, E355, C45E, 25CrMo4, 34CrMo4, 42CrMo4

4. Size Range

• Outer Diameter (OD): 80mm – 325mm

• Wall Thickness (WT): Customizable

• Length: As required

Custom 4140 hollow bar sizes available per project specs.

5. Manufacturing Methods

• Hydraulic cold drawing

• Hot rolled + deep hole boring

• Hot forged + deep hole drilling

6. Delivery Conditions

7. Turning & Machining Capabilities

We support complete custom part production from AISI 4140 / 42CrMo4 hollow bar, including:

• Rough turning

• CNC precision machining

• Polishing of ID/OD surfaces

• Thread & groove cutting

• Final finishing per drawing

8. Packaging & Marking

• Export-standard packaging (steel strip bundles)

• Oil-coated surfaces (inside and out)

• Custom logos & markings available on request

Key Features

✅ Wide range of 4140 hollow bar sizes in stock

✅ Precision tolerance and high roundness

✅ Strong fatigue & pressure resistance

✅ One-stop solution: raw bar + machining

✅ Suitable for critical industrial parts

 Applications

• Hydraulic cylinder barrels

• Press and heavy machine components

• Oil & gas equipment

• Axle and shaft assemblies

• Custom-engineered mechanical parts

FAQs

Q1: What sizes of 4140 hollow bar can you supply?

A: OD from 80–325mm, WT as required. Contact us for a detailed size chart.

Q2: Can you machine finished parts from hollow bars?

A: Yes, we provide full machining service based on drawings.

Q3: What’s your MOQ?

A: Typically 5 tons per size. Smaller projects negotiable.

Q4: Delivery time?

A: 30–45 days depending on material availability and machining specs.

Q5: How do you ensure quality?

A: Multi-stage inspection: chemical, mechanical, dimensional, NDT, and surface finish.

Company Profile

Chengxin is a trusted Chinese supplier of alloy steel hollow bars and precision cylinder parts. Established in 2002, we operate 12 workshops over 32,000㎡.

We provide:

• Hollow bars in a wide range of grades

• Custom CNC machined hydraulic parts

• Full traceability & export packaging

• Stable quality, on-time delivery, and international service