Hard Chrome Plated Bar and Tube
At Midland Special Steels, we supply high-quality hard chrome plated bars and tubes, engineered to meet the demanding requirements of modern hydraulic systems. These components play a crucial role in hydraulic cylinder performance — functioning as piston rods that convert hydraulic power into controlled linear motion while simultaneously protecting the internal system from abrasive contaminants and environmental wear.
Our chrome-plated bars and tubes are primarily used in piston rod applications, where the surface must meet strict standards for durability, corrosion resistance, and wear control. The steel grades we supply for this purpose are carefully selected and optimised in terms of both chemical composition and production process, ensuring they provide the mechanical performance necessary for demanding hydraulic environments while offering superior compatibility with hard chrome plating.
To deliver consistent results, all of our bars undergo thorough pre-treatment, plating, and finishing processes. These steps are closely controlled to guarantee an even distribution of micro-cracks in the chrome layer — a critical feature for effective lubrication and long-term corrosion protection. An optimal micro-crack pattern allows for controlled oil retention across the plated surface, supporting efficient interaction with seals while resisting surface degradation caused by friction, pressure, and exposure.
Before any product leaves our facility, it is subjected to rigorous quality assurance procedures. Each Cromax bar or tube is visually and dimensionally inspected, tested for micro-crack density, and verified for chrome thickness and hardness. Salt-spray testing is also carried out to confirm corrosion resistance under real-world conditions, covering various combinations of steel grades, heat treatments, rolling procedures, and plating batches. This attention to detail ensures every chrome-plated product we supply performs reliably under harsh operating conditions.
Where elevated corrosion resistance is required — such as in offshore, mining, or exposed outdoor applications — we offer specialised Cromax C and NiKrom variants. These enhanced plating options are designed to meet more aggressive corrosion standards, offering longer service life and greater protection in chemically or environmentally hostile environments. This makes them particularly well suited for use in equipment exposed to saltwater, industrial chemicals, or prolonged moisture exposure.
Advantages of Cromax and NiKrom
• In-house production facilitates deliver unmatched quality and consistency
• Optimsed to match the requirements in mechanical properties
• Every single production batch is verified in salt-spray testing
• High consistency and quality ensure well-functioning hydraulic systems
The integrity of a piston rod surface is vital not only for functionality but also for environmental and operational efficiency. Abrasive wear caused by contamination particles, both from outside the hydraulic system and from within, can lead to direct oil leakage and cause secondary damage to seals and internal components. Over time, this results in reduced system performance, increased maintenance, and potential environmental hazards due to fluid loss. That’s why consistency in plating thickness and surface hardness is key — and it’s also where our strict production and inspection processes provide peace of mind.
Cromax products are engineered for minimal variation in chrome thickness and surface hardness, both of which are essential for maintaining consistent seal performance and reducing component wear. Our bars and tubes also feature precise surface roughness and finish, offering ideal conditions for lubrication between rod and seal, further extending the life of the hydraulic system.
In addition to material quality, we also offer flexible sizing and fast turnaround. Our hard chrome plated bars and tubes are available in a range of standard diameters and lengths, with custom sizes available on request. All stock can be cut to length, machined to specification, or supplied with certified documentation for quality-critical or OEM applications.
Whether you’re maintaining hydraulic cylinders or manufacturing high-spec machinery, Midland Special Steels provides the reliability, performance, and technical support you need. Our chrome-plated solutions are trusted by industries across the UK and beyond — from heavy construction and plant hire to energy, rail, and precision manufacturing.
If you’d like to learn more about our hard chrome plated bar and tube range, including availability, specifications, or enhanced corrosion-resistant options, contact us today. Our knowledgeable team is on hand to help you find the right solution for your application.
Standard and Cromax steel grades
| Selection Criteria | Technical Data | |||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Steel Grades | Machinability | Fusion welding | Friction Welding | High Impact Requirements | EUR/Mpa Index | Dimension DIA. (mm) | Yield strength R/R (MPa) | Tensile Strength Rm (MPa) | Elongation A5 (%) | Hardness HB | Impact toughness KV (J) | Surface hardness IH HRC |
| 180X | Good | Quite Suitable | Suitable | No | 90 | 20-90 | > 500 | 750-950 | 16 | 220-270 | - | > 50 |
| 280X | Good | Suitable | Suitable | Yes | 60 | 20-90 91-125 > 125 | > 520 > 440 > 350 | 650-800 550-700 500-700 | 19 19 19 | 200-241 180-230 180-230 | > 27 at -20°c > 27 at -20°c > 27 at -20°c | > 45 |
| 4821H | Rather Good | Needs Care | Suitable | No | 55 | < 125 | > 580 | 850-100 | 14 | 250-300 | - | > 55 |
| 42CrMo4 | Moderate | Unsuitable | Suitable | Yes | 70 | < 40 40-95 > 95 | > 750 > 690 > 550 | 1000-1200 900-1100 800-950 | 11 12 13 | 295-355 265-325 235-295 | > 35 at 20°c > 35 at 20°c > 35 at 20°c | > 55 |
| TUBE | Good | Suitable | Suitable | Yes | N/A | > 450 | 550-800 | 20 | 160-240 | > 27 at -20°c | > 45 |
Cromax surfaces
| Corrosion resistance according to ISO 9227 | Technical data | ||||||
|---|---|---|---|---|---|---|---|
| Surface | AASS | NSS | CASS | Surface Roughness | Chrome thickness | Chrome hardness HV01 | |
| Ra (μm) | Rt (μm) | μm | |||||
| Cromax standard | Min 72h R9 | ** | ** | > 0.2 | > 2.0 | > 20 | > 850 |
| Cromax C | Min 120h R9 | ** | - | > 0.2 | > 2.0 | > 20 | > 850 |
| NIKROM 150 | Min. 150 h RIO | Min. 500 h R10 | - | > 0.2 | > 1.6 | Ni > 10 Cr > 20 | > 850 |
| NIKROM 500 | Min. 500 h R 1 0 | Min. 1500 h R10 | - | > 0.2 | > 1.6 | Ni > 30 Cr > 20 | > 850 |
**specified and verified according to agreement
