Three basic profiles, different production advantages
Round bar is a natural starting point for cylindrical components such as shafts, pins, rollers, bushings, sleeves, spacers, and turned machine parts. Hexagonal bar is often useful for nuts, couplings, fittings, and other parts that benefit from wrench flats. Square bar supports blocks, brackets, guides, jigs, fixtures, and key-stock-related parts.
The profile choice can reduce the amount of material removed before a part reaches its final geometry. It should still be checked against the finished drawing, machining allowance, material yield, and process capability.
Application reference table
Use this table to frame a conversation about candidate materials. It does not establish a material specification or approve a substitute for any particular component.
| Application | Typical form | Common grade references | Why the form is considered |
|---|---|---|---|
| Light-duty shaft | Round bar | SGD290D, SGD400D, SS400, AISI 1018 | A straightforward profile for general machining |
| Higher-load shaft | Round bar | S45C, AISI 1045 | Often considered where higher strength is needed |
| Nuts and fasteners | Hexagonal bar | SGD290D, SGD400D, AISI 1018 | Hex profile can reduce initial shaping |
| Bushings, sleeves, spacers | Round bar | AISI 1018, S20C, S45C | Suitable starting form for turning and boring |
| Brackets, jigs, fixtures | Square bar | SS400, AISI 1018, S20C | Square profile supports block and support geometry |
| Guides, key stock, support blocks | Square bar | S20C, S45C | A stable section for support components |
Move from a use case to an approved material
Before you order, translate the use case into a material specification: applicable standard, grade or approved equivalent, form, dimensions, tolerance, condition, quantity, delivery point, and required documentation. This keeps an application example from being mistaken for a final engineering decision.
Continue reading
Frequently asked questions
Which bar shape should I use for a bushing?+
Round bar is generally the most direct starting form for a bushing or sleeve because the part is commonly turned and bored. Confirm the grade, tolerance, material allowance, and wear requirements with the approved design.
Can one grade suit several applications?+
A grade may appear across several applications, but that does not make it automatically suitable. The finished part, loads, process, and quality requirements determine whether it is approved.
Should I select material based on shape or grade first?+
Start with the finished component and its specification. That lets you select both the appropriate grade and the profile that best supports the production process.
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.