ironpowerfitness

Weight Plates

SP004 Cast Iron Weight Plate

Solid Cast Iron Construction | Glossy Black Finish | 50.4mm Precision Bore | OEM Manufacturer


Product Overview

The SP004 Cast Iron Olympic Weight Plate represents the foundation of any serious strength training facility—a durable, reliable, and cost-effective plate engineered for longevity and performance. Manufactured from high-grade cast iron with a smooth glossy black finish, these plates offer exceptional durability at a competitive price point.

As the original manufacturer, we produce these plates with precision-machined 50.4mm bores for a perfect fit on Olympic and powerlifting barbells, bold weight markings for easy identification, and robust construction that withstands daily use in commercial and home gym environments.

Available in a full range from 0.5lb to 45lb, sold in pairs or complete sets, the SP004 is the go-to choice for fitness brands, gym chains, and retailers seeking quality cast iron plates without premium pricing.


1. Key Features

Feature Benefit
Solid Cast Iron Construction Durable, impact-resistant, built for heavy daily use
Glossy Black Finish Professional appearance, resists rust with proper care
Precision Machined Bore 50.4mm diameter – smooth fit on all Olympic and powerlifting barbells
Bold Weight Markings Clear, easy-to-read numbers for quick identification
Wide Weight Range 0.5lb to 45lb – accommodates all fitness levels and training programs
Sold in Pairs Balanced loading for symmetrical training

2. Material & Construction – Cast Iron Durability

Specification Detail
Material High-grade gray cast iron
Casting Method Sand casting with quality control on density and consistency
Finish Glossy black paint – smooth, professional appearance
Bore Precision machined after casting to 50.4mm ± 0.2mm
Weight Tolerance ±2% – industry standard for cast iron plates
Durability Withstands repeated use in commercial and home gym settings

3. Technical Specifications – SP004 Series

Parameter 0.5lb 1.25lb 2.5lb 5lb 10lb 25lb 35lb 45lb
Material Cast iron with glossy black finish
Bore Diameter 50.4mm ± 0.2mm (fits all Olympic barbells)
Weight Tolerance ±2% ±2% ±2% ±2% ±2% ±2% ±2% ±2%
Finish Glossy black paint
Sold As Pairs Pairs Pairs Pairs Pairs Pairs Pairs Pairs

4. Available Configurations

Individual Pairs

  • 0.5lb, 1.25lb, 2.5lb, 5lb, 10lb, 25lb, 35lb, 45lb

Complete Sets (Custom Configurations Available)

Set Type Contents
100lb Set Pairs of 5lb, 10lb, 25lb
160lb Set Pairs of 5lb, 10lb, 25lb, 35lb
250lb Set Pairs of 5lb, 10lb, 25lb, 35lb, 45lb
300lb Set Pairs of 5lb, 10lb, 25lb, 35lb, 45lb (additional 45lb pairs)

Custom sets available for wholesale orders.


5. Manufacturing Process

As the actual manufacturer, we maintain full control over production quality:

  1. Raw material sourcing: High-grade pig iron and scrap steel, verified composition

  2. Casting: Precision sand casting with density control

  3. Cooling & finishing: Controlled cooling to prevent stress fractures

  4. Machining: CNC bore machining to 50.4mm ± 0.2mm

  5. Surface preparation: Cleaning, deburring, and primer application

  6. Painting: Glossy black powder coat or liquid paint finish

  7. Weight verification: Batch sampling with calibrated scales

  8. Packaging: Pairs packed in cartons or bulk export packaging


6. Customization Solutions – OEM/ODM

Customization Aspect Options Available
Logo / Branding Silkscreen printed; Laser engraved; Embossed during casting
Weight Markings Custom fonts, colors, or engraved markings
Finish Glossy black (standard); Matte black; Custom colors
Packaging Pairs in color boxes; Sets in branded cartons; Bulk export pallets
Set Configurations Custom weight combinations per your market needs
Weight Tolerance Standard ±2%; Tighter tolerance available upon request

Minimum Order Quantities:

  • Standard finish (black): 50 pairs per weight (mixable across weights)

  • Custom logo/finish: 100 pairs per weight (negotiable)

Lead Time:

  • Sample order: 2–3 weeks

  • 20FT/40HQ container: 4–5 weeks

  • Custom branding: 5–6 weeks


7. Quality Control

Test Method Standard
Weight Accuracy Batch sampling with calibrated scales ±2%
Bore Fit 100% gauge testing 50.4mm ± 0.2mm
Finish Adhesion Cross-hatch tape test No peeling
Dimensional Check Random sampling Consistent diameter and thickness
Durability Drop test on concrete No cracking or deformation

8. Production Capacity

Capacity Metric Specification
Casting Capacity 100+ tons per day
Machining Capacity 10,000+ bores per day
Monthly Output 50,000+ pairs (100,000+ plates)
Annual Capacity 600,000+ pairs

9. Packaging Solutions

Retail-Ready Packaging (Pairs)

  • Color box with product information and branding

  • Individual wrapping to protect finish

  • Labeling with SKU, weight, and barcode

Bulk Export Packaging (Wholesale)

  • Heavy-duty export cartons – 2–4 pairs per carton

  • Shrink-wrapped pallets with edge protectors

  • Container optimization: 20GP / 40HQ loading plans provided


10. Target Applications & Customer Segments

Customer Type Value Proposition
Fitness Brands (OEM) Custom branding, retail-ready packaging, consistent quality
Gym Chains Bulk pricing, durable construction for high-traffic facilities
E-Commerce Retailers Mix-and-match container orders, ready-to-ship packaging
Commercial Gyms Affordable, reliable plates for member use
Home Gym Retailers Complete sets, competitive wholesale pricing

11. Why Choose Us as Your Manufacturer?

Advantage Benefit
True Manufacturer Direct factory access—no middleman margins
Casting Expertise In-house foundry with quality control on every batch
Precision Machining CNC bore finishing ensures consistent barbell fit
Customization Ready Full OEM capabilities—logo, finish, packaging
Scalable Production Capacity for both small custom runs and high-volume container orders
Global Export Experience Proven logistics to North America, Europe, Australia, Asia

Details