OEM Black Oxide Steel Timing Pulley Bars

Streamline your custom timing pulley production with our OEM black oxide steel timing pulley bars—precision-ground, pre-hardened bar stock engineered for machining into finished pulleys. Also known as timing pulley blanks or custom pulley bar stock, these ready-to-machine bars eliminate the need for raw round stock preparation, reducing your setup time and material waste. Manufactured from high-grade carbon or alloy steel with a uniform black oxide finish, they provide corrosion resistance and a professional appearance. Ideal for OEM manufacturers, machine shops, and automation component suppliers producing custom-bored, special-tooth-count, or non-standard timing pulleys for CNC machines, robotics, packaging equipment, and conveyor systems.

Ready-to-Machine Design Cuts Production Lead Time

Pre-ground to precise outer diameter tolerances and pre-bored with a pilot hole (if specified), our timing pulley bars arrive ready for tooth hobbing, final boring, keyway cutting, and set screw drilling. This eliminates raw stock preparation, reduces machining steps by up to 40%, and accelerates your custom pulley production.

Black Oxide Finish for Corrosion Resistance & Professional Finish

The uniform black oxide coating provides moderate corrosion protection (24-72 hours salt spray resistance) and an attractive matte black appearance that requires no additional finishing. This surface treatment also reduces galling during machining and improves lubricant retention on finished pulley teeth.

High-Grade Steel for Wear Resistance & Dimensional Stability

Manufactured from C45 (1045) carbon steel for general-duty applications or 40Cr/20CrMnTi alloy steel for high-load, high-wear environments. All bars are pre-heat-treated to achieve 25-35 HRC (pre-hardened) or 45-55 HRC (fully hardened on tooth contact areas after final machining), ensuring finished pulleys maintain tooth profile accuracy under continuous operation.

Precision OD Tolerances for Accurate Tooth Cutting

Outer diameters are ground to h7 or h9 tolerances (typically ±0.02mm to ±0.05mm), providing a true, concentric surface for tooth hobbing or grinding. This ensures finished pulleys achieve DIN 7-9 accuracy grades, minimizing backlash and vibration in high-speed drives.

Available in All Standard Pitch Profiles

Bar stock is available pre-hobbed with timing pulley tooth profiles including HTD (3M/5M/8M/14M), T (T5/T10/T20), AT (AT5/AT10/AT20), STD, XL, L, H, and metric profiles. Uncut bar stock is also available for custom tooth forms.

Our timing pulley bars are manufactured under ISO9001:2015 certified processes. Raw materials are fully traceable with mill test reports (MTR) available. Black oxide coating is RoHS and REACH compliant, containing no hazardous heavy metals. Heat treatment records and hardness profiles are available upon request. We can provide third-party inspection reports (SGS, TÜV) for export verification.

Outer Diameter Range: 10mm to 200mm (custom up to 300mm), depending on tooth profile and tooth count requirements.

OD Tolerance Options: h7 (±0.015mm for diameters 30-50mm), h8 (±0.022mm), or h9 (±0.030mm). Specify based on your bearing fit or mounting requirements.

Pre-Hobbed vs. Plain Bar: Choose pre-hobbed bar stock with finished timing pulley teeth (saving your hobbing step) or plain round bar for custom tooth profiles. Pre-hobbed bars are available for HTD, T, AT, XL, L, and H profiles.

Heat Treatment Options:

Through-hardened (25-35 HRC): Suitable for moderate-load applications where tooth wear is not critical.

Induction-hardened teeth (45-55 HRC): Recommended for high-cycle, high-load drives; case depth 0.8-1.5mm.

Carburized (58-62 HRC): For maximum tooth surface hardness; requires finish grinding after heat treatment.

Length Options: Standard 300mm, 500mm, 1000mm bars. Custom lengths cut to your CNC lathe workholding requirements.

Pilot Bore Options: If specified, pilot bores are drilled to H7 tolerance (e.g., 10mm, 12mm, 15mm, 20mm, 25mm) for initial shaft mounting during tooth hobbing.

Black Oxide Performance: Salt spray resistance (ASTM B117): 24-72 hours depending on post-treatment sealing. Provides temporary in-process corrosion protection during storage and machining, and a finished appearance on final pulleys.

Centerless Ground (Option): For applications requiring ultra-precise OD, we offer centerless grinding to h6 tolerances (±0.008-0.010mm).

We offer a 12-month warranty against material defects, including hard spots that affect machinability or surface cracks in the bar stock. Our technical support team provides expert assistance with heat treatment selection, machining recommendations (cutting speeds, tooling), and post-machining tooth hardening guidance. For OEM and volume orders, we offer pre-production bar samples for machining validation and can provide custom lengths, pre-hobbed profiles, or special pilot bore configurations with competitive lead times. We maintain stock of popular OD sizes and profiles (HTD 5M/8M, T10, XL, L) for rapid dispatch. For any quality concerns, our clear return and replacement policy ensures minimal disruption to your production schedule. We also offer end-cutting and chamfering services to further simplify your setup.