Start with the component—not a generic material label
A practical material request starts with what the finished part must do. A shaft may need to transmit rotation and fit bearings or couplings; a bushing may need controlled internal diameter and a compatible wear surface; a fastener may need a profile that reduces machining steps; and a fixture may need a stable, machinable support section.
Use the component drawing, process route, service condition, and approved material specification to decide which profile and grade should be evaluated. The examples below are common starting points for discussion, not automatic grade recommendations.
Round bar: cylindrical and turned components
Round bar is commonly considered for shafts, spindles, pins, rollers, bushings, sleeves, spacers, and other cylindrical machine components. It provides a direct starting form for turning, drilling, boring, threading, and related machining operations.
The suitable grade depends on the part’s load, fatigue, surface, fit, treatment, and production requirements. Specify the finished dimensions and machining allowance so the raw-stock size can be assessed correctly.
- Shafts and spindles
- Pins, rollers, and axles
- Bushings, sleeves, and spacers
- Turned machine parts and selected automotive or heavy-equipment components
Hexagonal bar: wrench flats and efficient starting geometry
Hexagonal bar is commonly considered for nuts, couplings, fittings, special fasteners, and components that need wrench flats or a six-sided profile. Starting from the appropriate profile can reduce preliminary shaping for a suitable design.
Confirm the required across-flats size, machining allowance, grade, tolerance, thread or fit requirement, quantity, and delivery conditions before selecting an offered product line.
- Nuts and fasteners
- Couplings and fittings
- Components with wrench flats
- Machined parts where a six-sided raw profile improves material use
Square bar: blocks, supports, guides, and fixtures
Square bar is commonly considered for brackets, support blocks, guides, jigs, fixtures, key-stock-related parts, and general fabrication components. Its square profile can simplify work on parts with flat faces and right-angle geometry.
The raw section still needs to provide enough material for machining, bending or fabrication, and the required finish. Confirm the final drawing, grade, size, length, quantity, and documentation requirement before purchasing.
- Brackets and support parts
- Jigs and fixtures
- Guides and key-stock-related components
- Spacer blocks and general fabrication parts
Turn a use case into a purchase-ready request
A use case is useful when it becomes a defined scope. Bring together the part drawing, grade or governing standard, bar form, nominal dimensions, allowance, quantity, delivery location, and any MTC or inspection requirement before you compare quotations.
- State the finished component and its production process
- Name the governing grade or standard and approved alternatives
- Specify the bar form, raw dimensions, finished dimensions, and quantity
- Include tolerance, surface, heat-treatment, document, and delivery requirements that affect acceptance
Continue reading
Steel-bar product range
Review the listed bright and black bar product categories, grade references, and size ranges.
Read the guideApplications by shape and grade
Use an application reference table to prepare a more precise material discussion.
Read the guideSteel-bar buyer’s guide
Bring the technical and delivery details into one purchase-ready request.
Read the guideFrequently asked questions
Which bar shape should I use for a shaft?+
Round bar is generally the direct starting form for a shaft. The final selection should account for grade, raw-stock allowance, straightness, tolerance, treatment, and the approved component drawing.
Are use cases a substitute for a material specification?+
No. They help frame an enquiry around the intended part and process. Engineering and quality approval must still be based on the governing drawing, standard, and project requirements.
Can one grade be used across several product use cases?+
A grade can appear in multiple applications, but it is not automatically appropriate for each one. Confirm the functional, process, documentation, and inspection requirements for the specific component.
Start with the specification that matters
Send the grade, shape, diameter or section size, quantity, and delivery location via WhatsApp. CV Tanamas can help you check the relevant supply path before you issue a purchase order.