Overview of Hydraulic Tubes and Rods

1. 20MnV6 Round Steel (Plain and Induction Hardened)

Material Information:

• 20MnV6 is a vanadium micro-alloyed carbon-manganese steel, usually supplied as cold-drawn or hot-rolled bars.

• Mechanical properties (cold-drawn state): tensile strength 550–790 MPa, yield strength approx. 430 MPa, elongation ≥ 17%, Brinell hardness HB ≥ 170.

• Induction hardened variant: surface hardness up to HRC 60–65, inner core retains toughness.

Application:
Piston rods, bearing housings, eccentric shafts, especially where combined wear and impact resistance is important.

2. 42CrMo4 Alloy Steel (Plain and Hardened)

Material Information (Plain):

• 42CrMo4 (EN 1.7225) chromium-molybdenum alloy steel excellently combines strength and toughness even in its plain, pre-heat treatment state.

• Mechanical properties in plain condition: tensile strength 650–850 MPa, yield strength ≥ 440 MPa, elongation ≥ 12%.

• Application: general machine parts, shafts, V-belt pulley supports, where consistently high strength is important.

Heat Treatment Characteristics (Hardened Variant):

• The rods are first heated to high temperatures, then rapidly cooled and tempered, so the surface hardness reaches HRC 53 (Ø ≤ 60 mm), and the inner core retains sufficient toughness and impact resistance.

• In case of induction hardening, the surface hardness is also ≥ HRC 53, while the core remains even more flexible due to the heat treatment cycle.

• Application: heavy-duty piston rods, eccentric shafts, and other high-cyclic components.

Application:
Heavy-duty piston rods and shafts where internal flexibility is critical, and components requiring surface hardness.

3. CK45 Carbon Steel (Plain and Hardened)

Material Information:

• CK45 (DIN 1.1191) is a medium carbon steel (C ≈ 0.45%) with good tensile strength (570–700 MPa) and Brinell hardness (HB 170–210).

• Excellent machinability and weldability in normalized (plain) condition; for induction hardened variant, surface hardness is around HRC 55–60.

Application:
Machine parts, eccentric components, in areas where the surface needs to be hardened only partially for higher wear resistance.

4. Stainless Round Steels (1.4301 and 1.4057)

1.4301 (AISI 304)

• Composition: 17.5–19.5% Cr, 8–10.5% Ni, C ≤ 0.07%.

• Mechanics: tensile strength 520–720 MPa, yield strength ≥ 210 MPa, elongation ≥ 45%.

• Application: food and pharmaceutical hydraulics, where corrosion and chemical resistance are primary.

1.4057 (AISI 431)

• Composition: 15–17% Cr, 2–2.5% Ni, 0.12–0.22% C, smaller Mo, Si, P additives.

• Mechanics: capable of martensitic transformation, as drawn material HRC 40–50, outstanding torsional strength.

• Application: high-strength, corrosion- and fatigue-resistant shaft solutions, piston rods in contact with chemical media.