Drawn Over Mandrel (DOM) Acier: The Guide to Manufacturing, Propriétés & Usages

If you need strong, precise seamless tubing for hydraulic cylinders, pièces automobiles, or structural frames, drawn over mandrel (DOM) acier est l'étalon-or. Unlike welded or standard seamless tubing, DOM steel has a uniform wall thickness and smooth inner surface—making it ideal for high-pressure and precision applications. Ce guide décompose tout ce que vous devez savoir pour choisir, utiliser, and source DOM steel effectively.

1. Drawn Over Mandrel (DOM) Acier: Manufacturing Techniques

DOM steel’s superior quality starts with a rigorous, multi-step manufacturing process. Here’s how it’s made, from raw material to finished tubing:

1. Start with Seamless Steel Tubing: The process begins with seamless steel tubing (made via extrusion or piercing). This ensures no weld seams, which can weaken tubing under pressure.
2. Recuit: The seamless tubing is heated to 800–900°C and cooled slowly (recuit). This softens the steel, making it easier to shape during drawing.
3. Mandrel Insertion: A solid metal rod called a mandrel is inserted into the seamless tubing. The mandrel keeps the tube’s inner hole open and ensures uniform inner diameter (ID) during drawing.
4. Cold Drawing: The tubing (with mandrel inside) is pulled through a series of décède (shaped openings) in a drawing machine. This reduces the outer diameter (OD) and wall thickness while stretching the tube to length. Travail au froid during this step strengthens the steel.
5. Garniture & Coupe: After drawing, the tubing is cut to standard lengths (Par exemple, 6ft, 12ft) or custom sizes using precision saws.
6. Final Heat Treatment: Optional but common—another round of annealing to reduce stress from cold drawing, or tempering to boost hardness for wear-prone parts.
7. Inspection: The finished DOM tubing undergoes dimensional checks (OD, ID, wall thickness) and surface inspections to ensure quality.

Vrai exemple: A hydraulic cylinder manufacturer in Germany uses DOM steel tubing. Leprecision manufacturing process ensures the tubing can handle 3,000 psi of hydraulic pressure without leaking—critical for heavy machinery.

2. Drawn Over Mandrel (DOM) Acier: Propriétés des matériaux

DOM steel’s unique manufacturing process gives it standout properties that make it better than welded or standard seamless tubing. Voici comment ça fonctionne:

Propriété clé: Précision dimensionnelle

DOM steel’sdimensional accuracy is its biggest strength. Par exemple, a 10mm OD DOM tube has an OD tolerance of just ±0.05mm—this means it will fit perfectly with connectors or bearings, no extra machining needed. Welded tubing, en revanche, often has ±0.2mm tolerance, requiring additional work.

Material Composition

Most DOM steel is mild carbon steel (AISI 1018 is common) avec:

• Carbone (C): 0.15–0.20% (balances strength and ductility)
• Manganèse (MN): 0.60–0.90% (boosts tensile strength)
• Fer (Fe): 98–99% (base metal)
  For corrosion-resistant needs, stainless steel DOM tubing (SUS304/SUS316) est disponible, with chromium (18–20%) and nickel (8–10%) added to prevent rust.

3. Drawn Over Mandrel (DOM) Acier: Applications and Uses

DOM steel’s strength, précision, and seamless design make it essential in industries where reliability matters. Voici ses utilisations les plus élevées:

Machines industrielles

• Cylindres hydrauliques: DOM tubing’s smooth inner surface reduces friction between the piston and tube, preventing leaks. A construction equipment maker uses DOM steel for excavator hydraulic cylinders—they last 50% longer than those made with welded tubing.
• Pneumatic cylinders: Similar to hydraulic cylinders, DOM steel handles compressed air pressure without bursting.

Industrie automobile

• Suspension components: DOM steel bars make up sway bars and control arms—their high tensile strength resists bending during sharp turns.
• Arbres d'entraînement: DOM tubing’s uniform wall thickness ensures balanced rotation, reducing vibration in cars and trucks.

Construction & Structural

• Furniture frames: DOM steel tubes are used for heavy-duty office chairs and gym equipment—they’re strong but lightweight. A fitness brand uses DOM steel for treadmill frames; the tubes support 300kg of weight without bending.
• Tubular structures: DOM steel forms railings and support posts in buildings—its straightness (±0.5mm per meter) ensures a clean, regard professionnel.

Utilisations spécialisées

• Marine applications: Stainless steel DOM tubing resists saltwater corrosion, making it ideal for boat rigging and hydraulic systems.
• Équipement médical: DOM steel is used for surgical tool handles—its smooth surface is easy to sterilize and doesn’t harbor bacteria.

4. Drawn Over Mandrel (DOM) Acier: Quality and Standards

To ensure you’re getting high-quality DOM steel, look for compliance with global standards and strict quality control measures.

Normes clés

Mesures de contrôle de la qualité

Reputable manufacturers use these steps to ensure DOM steel quality:

1. Chemical Analysis: Tests check for carbon, manganèse, and other alloying elements to confirm they meet specs (Par exemple, 0.18% carbon for AISI 1018).
2. Inspection dimensionnelle: Calipers and laser scanners verify OD, ID, wall thickness, and straightness—ensuring they stay within tolerance.
3. Tests non destructeurs (NDT): Ultrasonic testing checks for internal defects (Par exemple, fissure) that can’t be seen with the naked eye.
4. Inspection de surface: Visual checks or profilometers ensure the outer and inner surfaces are smooth (no scratches or pits).
5. Mechanical Testing: Tensile tests measure strength, while bend tests check ductility—samples are pulled or bent until they break to confirm performance.

Pour la pointe: Always ask for a Certificate of Compliance (Coc) or Mill Test Report (MTR) when buying DOM steel. These documents prove the tubing meets your chosen standard.

Perspective de la technologie Yigu

À la technologie Yigu, Nous recommandonsdrawn over mandrel (DOM) acier for clients needing high-pressure, precision tubing. We supply ASTM A513 DOM steel (mild steel and stainless steel) with tight tolerances (±0.03mm for wall thickness) for hydraulic and automotive projects. Our quality checks include ultrasonic NDT and dimensional scans, so clients trust the tubing can handle tough conditions. We also offer custom cutting to reduce waste—for example, a hydraulic client saved 15% on material costs by ordering 8ft custom lengths instead of standard 12ft tubes.

FAQ

1. Is DOM steel better than seamless steel for hydraulic cylinders?
   Yes—standard seamless steel has less uniform wall thickness (± 0,1 mm de tolérance) and a rougher inner surface. DOM steel’s ±0.05mm tolerance and smooth ID reduce friction and leaks, making it more reliable for hydraulic systems.
2. Can DOM steel be bent or welded?
   Yes—DOM steel is ductile enough for bending (use a tube bender to avoid kinks). It also welds well with MIG or TIG welding, but preheat to 150–200°C first to reduce stress from cold working.
3. How do I choose between mild steel and stainless steel DOM tubing?
   Choose mild steel DOM for indoor, dry applications (Par exemple, meubles, pièces automobiles)—it’s cheaper. Choose stainless steel DOM for outdoor, mouillé, or corrosive environments (Par exemple, marin, médical)—it resists rust but costs more.