45 Steel Induction-Hardened Chrome Shaft
- Base
- Grade 45, induction-hardened case ≥ HRC55, ≈ 2 mm deep · Ø4–130 mm
- Choose it when
- The rod surface takes the wear and guidance load, and little machining follows after supply.
PISTON ROD BAR
Hard chrome piston rod bar for hydraulic cylinders
Chrome-plated bar for hydraulic and pneumatic cylinder rods, supplied to a negative diameter tolerance in full bars up to 8.1 m or cut to length from 200 mm. Choose the base first — induction hardened, or quenched and tempered in grade 45, 40Cr or 42CrMo — then the chrome thickness and tolerance.
0120–30 μmhard chrome per side, up to 50 μm
02HV800+chrome hardness capability
03Ra ≤ 0.4 μmchrome surface roughness
04≈ 2 mminduction-hardened case, ≥ HRC55
Typical process capability. Final values for each size are fixed on the confirmed drawing, specification and order.
CHOOSE THE ROD BASE
Five bar routes for piston rods: pick by load, wear and machining
The chrome layer is the sealing surface; the base underneath carries the load. On all five routes the hard chrome is plated by a long-term partner plant to Yixin's specification.
45 Steel Q&T Chrome-Plated Bar
- Base
- Grade 45 Q&T, surface hardness HRC25–28 or 28–32 per order · Ø8–140 mm
- Choose it when
- You want a quenched-and-tempered base under the chrome and plan to machine the rod ends.
40Cr Q&T Chrome-Plated Bar
- Base
- 40Cr Q&T, HRC28–35 · Ø8–140 mm, made to order
- Choose it when
- The drawing specifies 40Cr, or the load calls for a stronger Q&T base than grade 45.
42CrMo Q&T Chrome-Plated Bar
- Base
- 42CrMo Q&T, HRC30–38 · Ø8–100 mm, from 1 t, 7–10 days
- Choose it when
- Heavy or shock loads, or the drawing specifies 42CrMo.
45 Steel Chrome-Plated Soft Shaft
- Base
- Grade 45, not hardened, base ≈ HRC17 · Ø4–140 mm from stock
- Choose it when
- Light-duty rods whose ends need substantial machining; not for rods that need an induction-hardened case.
Not sure which base?
Send the rod drawing with load, stroke and working conditions. We suggest a route in the quotation.
Send the drawingSPECIFICATION
Piston rod bar: standard specification
Standard values. Other sizes, tolerances and chrome layers are quoted against your drawing.
| Grade | 45 (GB/T 699-2015); 40Cr, 42CrMo (GB/T 3077-2015) · comparable, for reference only: C45, S45C, SAE 1045; 41Cr4, SCr440; 42CrMo4, SCM440 |
|---|---|
| Diameter | Induction hardened Ø4–130 mm · grade 45 and 40Cr Q&T Ø8–140 mm · 42CrMo Ø8–100 mm · not hardened Ø4–140 mm from stock, up to Ø200 mm made to order |
| Tolerance | Ø4–11: −0.02/−0.05 mm · from Ø12: 0/−0.02, −0.01/−0.03 or −0.02/−0.05 mm. If your drawing gives an ISO fit (for example f7), state it in the RFQ and we confirm the matching band |
| Hard chrome | 20–30 μm per side for export orders, up to 50 μm on request; chrome hardness up to HV800+ |
| Surface roughness | Chrome Ra ≤ 0.4 μm |
| Straightness | ≈ 0.1 mm/m from Ø25 · ≈ 0.2 mm/m below Ø25 |
| Length & cutting | Full bars 4 m, 6 m, 7.5 m or 8.1 m; CNC saw cut to length from 200 mm (≈ 3 mm allowance), ends left as sawn; end machining assessed from your drawing |
| Certificates & testing | Steel mill certificate for each heat, forwarded unaltered; third-party testing commissioned per order on request |
RFQ CHECKLIST
What to send for a piston rod quotation
With these seven items we reply with grade, tolerance, chrome thickness and lead time within one working day.
- Diameter and tolerance
Rod diameter, plus the tolerance band or the ISO fit on your drawing.
- Length and quantity
Finished length per piece and number of pieces, or total tonnes.
- Rod base
Grade and condition: induction hardened, Q&T (45, 40Cr, 42CrMo) or not hardened.
- Chrome and surface
Chrome thickness per side and surface roughness, if your design fixes them.
- End machining
Threads, chamfers or centre holes — attach the drawing.
- Inspection and documents
Mill certificate, any third-party test, and the report format you need.
- Packing and port
Sea-freight packing, FOB Shanghai or Ningbo, and your destination port.
INDEPENDENT VERIFICATION
Intertek onsite assessment
Production and trading assessed on site in June 2026, valid to June 2027.
Published lab reports
Sample bars tested for chemistry, hardness, case depth, roughness and roundness; each result applies to the tested sample only.
Chrome surface Ra 0.128 μm
Measured on a submitted sample by Jiangsu Third Party Measurement Technology (CNAS L11694); applies to that sample.
SERVICE
Export terms
How standard orders are handled. Volume and special requirements are written into the quotation.
- Minimum order
- 1 t per order; 20–50 kg sample orders available
- Lead time
- Cut-to-length from stock 3–5 days · non-standard diameters 7–10 days · custom heat treatment 10–20 days · 42CrMo 7–10 days, plus sea-freight booking
- Trade & payment
- FOB Shanghai or Ningbo · T/T
- Packing
- Protective film, steel-strapped bundles, wooden cases or pallets for sea freight
- Documents
- Commercial invoice, packing list and mill certificate; certificate of origin arranged per order; third-party inspection on request
- Response
- Quotation reply within one working day
PISTON ROD FAQ
Questions buyers ask about piston rod bar
01How thick is the chrome on your piston rod bar?
20–30 μm per side for export orders, up to 50 μm per side on request. Chrome hardness reaches HV800+. State the thickness on your drawing or RFQ; it is confirmed in the quotation.
02Induction-hardened or quenched-and-tempered rod: which one?
An induction-hardened rod (case ≥ HRC55, about 2 mm deep) puts the hardness at the surface, under the chrome, for wear and guidance. A Q&T rod (grade 45, 40Cr or 42CrMo) gives a stronger, tougher base for loaded rods and leaves the ends easier to machine. Choose by load, wear and how much machining follows.
03Can you supply rods cut to length?
Yes. Full bars come in 4 m, 6 m, 7.5 m or 8.1 m lengths, and we cut to length from 200 mm on CNC saws with about 3 mm allowance; the ends are left as sawn by default. End machining is assessed from your drawing.
04What is the minimum order?
1 t per order. Sample orders of 20–50 kg are available to check the bar before a full order.
05Are your grades the same as C45 or 42CrMo4?
Grade 45 is made to GB/T 699-2015, 40Cr and 42CrMo to GB/T 3077-2015. C45, S45C and SAE 1045; 41Cr4 and SCr440; 42CrMo4 and SCM440 are comparable grades for reference only — the chemistry ranges differ. The steel mill certificate for each heat is forwarded unaltered.
06What are your lead times?
Cut-to-length from stock: 3–5 days. Non-standard diameters: 7–10 days. Custom heat treatment: 10–20 days. 42CrMo: 7–10 days. Sea-freight booking time is added.
READY TO QUOTE