Because the grade number drives both price and performance, this selector puts a grade ladder, a size coverage map and a material cross-reference in one place for buyers working from a drawing, a worn part, or a distributor shelf. The stocked envelope runs from 9.0mm to 15.875mm in hardened AISI 52100 / GCr15 / SUJ2 / 100Cr6, so most fractional callouts inside that band can be covered by a single G40 bearing chrome steel balls line item, while general industrial assembly programs that need repeatable hardness and controlled tolerance can standardise on the same family of bearing chrome steel balls instead of sourcing several part numbers one at a time.
A G40 bearing chrome steel ball is a hardened steel rolling element made to the G40 grade — described on the product page as indicating tight tolerance and surface quality suitable for many rolling element applications. It is tighter than G100 and looser than G10, so it suits general rolling-element duty where stable hardness and predictable wear life matter more than sub-micron precision.
The same page frames the material as a proven high-carbon chromium steel known for hardness, contact fatigue resistance, and dimensional stability under repetitive load. In practice, that means the decision usually comes down to two questions: which grade band your application actually needs, and which diameter inside the 9.0mm–15.875mm range your drawing calls out. The modules below answer both, then hand the numbers back to you for a quote.
Grade numbers describe relative tolerance tightness on a rising scale — the lower the number, the tighter the band. Use this ladder as engineering guidance when you are deciding whether to release a drawing at G40 or step up. The G40 row is the product the page is built around; the surrounding grades show what you gain and give up by moving.
| Grade | Tolerance band | Typical duty | Typical application | Choose this grade when… |
|---|---|---|---|---|
| G10 | Highest speed, lowest noise and runout targets | Precision spindle and instrument bearing sets | Runout, vibration or noise is a stated requirement and the budget allows it | |
| G16 | Precision rotation, demanding but not extreme | Precision bearing sets, higher-grade linear motion | Standard grade is not enough but G10 would be overspecified | |
| G28 | General precision rotation, moderate speed and load | Mid-grade bearings, general machinery | You want a step above standard without full precision pricing | |
| G40 This product | Moderate speed with load capacity as the priority | Bearing production, repair and MRO stock, distributor inventory, general industrial assembly | You need traceable material and repeatable hardness more than sub-micron geometry | |
| G100 | Lower speed, higher load, cost-sensitive | Utility and general-duty bearings, non-critical rolling contact | Cost and availability drive the decision and running speed is low |
Band labels above are comparative guidance for selection. Exact grade limits are defined by the applicable ABMA / ISO 3290 or factory datasheet and by the DIN, AISI and GB standard the product page lists — confirm numeric limits with the supplier before releasing a drawing. The only tolerance claim carried on the product page itself is qualitative: tight tolerance and surface quality suitable for many rolling element applications.
These branches turn the ladder into a go/no-go. Each one ends in a plain verdict you can act on.
G40 is described as delivering controlled tolerance and wear resistance with stable hardness — the combination that matters when contact load, not rotational speed, sets the failure mode.
Verdict: G40 is usually the right call; reserve G10 for high-speed spindles.
Hardness HRC60-66, a grinding surface, DIN / AISI / GB standard and ISO & RoHS certification give a repeatable, documentable part. That is what a production or MRO program needs more than a tighter micron band.
Verdict: Specify G40 and hold the documentation; do not pay for precision you will not measure.
The 9.0mm–15.875mm envelope is wide enough to cover multiple part specifications from one line, which is exactly how the page positions the product for repair inventory and distributor stock.
Verdict: Stock G40 across the range; step to a tighter grade only when runout is written on the drawing.
These are the parameters a buyer, maintenance engineer or counter clerk needs when matching a callout to a part number. Everything below is taken from the product page for the 9.0mm–15.875mm G40 range.
| Material | AISI 52100 / SUJ2 / GCr15 / 100Cr6 |
|---|---|
| Grade | G40 |
| Size range | 9.0mm – 15.875mm |
| Hardness | HRC60-66 |
| Standard | DIN / AISI / GB |
| Surface | Grinding |
| Certification | ISO, RoHS |
| Function | Solid |
| Model | cd1358 |
| Country of origin | Shandong, China |
| Package | Cardboard box + pallet |
| Sales unit | Multiple of 20 |
| Batch packaging | 31 × 21 × 12 cm · 20.500 kg total per batch |
The range is quoted in metric, but plenty of drawings and repair sheets still arrive in fractional inches. The conversion column below helps you check whether a callout falls inside the envelope before you request pricing.
| Metric | Imperial equivalent | Where it shows up |
|---|---|---|
| 9.0 mm | ≈ 0.354 in | Bottom of the stocked range |
| 9.525 mm | 3/8 in | Common fractional bearing callout |
| 11.113 mm | 7/16 in | Common fractional bearing callout |
| 12.700 mm | 1/2 in | Common fractional bearing callout |
| 14.288 mm | 9/16 in | Common fractional bearing callout |
| 15.875 mm | 5/8 in | Top of the stocked range |
Confirm the exact diameters currently produced and packed before ordering — the range above describes the envelope, not a promise that every intermediate size is held in stock. For larger diameters in the same chrome steel family, the site also lists a GCr15 range at 31mm, 45mm, 46mm and 47mm.
Drawings arrive from different markets, so the same bearing steel appears under several designations. On this product page, AISI 52100, GCr15, SUJ2 and 100Cr6 all refer to the same high-carbon chromium steel the balls are made from — a proven grade known for hardness, contact fatigue resistance, and dimensional stability under repetitive load.
If your specification names stainless or ceramic instead, note that the page compares chrome steel to stainless steel bearing balls and states chrome steel is often selected when higher hardness and load-focused performance are the priority in controlled operating environments.
Match your buying situation to the specification feature that answers it, then to the order you should place. This is the module to send to whoever signs the requisition.
| Your scenario | Specification that answers it | What to order | Watch out for |
|---|---|---|---|
| Bearing production line | Grade G40 with HRC60-66, grinding surface, DIN / AISI / GB standard, ISO & RoHS certification | G40 chrome steel balls at the diameters on the drawing, inside 9.0–15.875mm, ordered in multiples of 20 | Check whether the drawing actually specifies G10 or G16 — G40 will not satisfy a written precision callout |
| Repair / MRO inventory | Controlled tolerance, wear resistance and stable hardness that reduce surface wear during regular service | A multi-diameter restock across the 9.0–15.875mm range rather than one size at a time | Do not mix chrome and stainless in the same bin — the page positions them for different duty |
| Distributor counter stock | Material traceability and repeatable mechanical performance from a single production source | Consolidate several customer part specifications onto one G40 line in one batch size | Convert imperial customer callouts to metric using the size module before quoting |
| General industrial assembly | Controlled tolerance and smooth rolling contact for solid rolling elements | G40 where runout is not written into the assembly specification | Step to a tighter grade only when noise or runout is a stated acceptance criterion |
Consistency across a repeat order usually matters more than any single parameter. The product page defines a batch as a multiple of 20 units, packed in cardboard boxes on a pallet measuring 31 × 21 × 12 cm and weighing 20.500 kg in total — a predictable unit for warehousing and freight planning.
The supplier states it has been established since 1998 with production and marketing experience, SGS / ROHS certification, advanced production and testing equipment, and technical personnel with more than ten years of production experience. For a repeat production program, use the batch unit above to size your warehouse slot and your first purchase order.
Send the diameter, the grade on your drawing and the quantity you plan to hold, and the supplier can confirm availability, lead time and pricing against the current production run.
The product page carries a GET A QUOTE action and the header links straight to a quote form. Include diameter, grade and quantity for a same-thread answer.
Request a quote →Batches ship in multiples of 20 at 20.500 kg per cardboard-box batch on a pallet, which makes multi-diameter consolidation straightforward for distributors.
See batch details →If your callout falls outside 9.0–15.875mm, or names a material other than chrome steel, describe the requirement and ask what the supplier can match.
Describe your requirement →Confirm the diameters inside the 9.0–15.875mm envelope, lock the grade against your drawing, and request pricing for the batch quantity you plan to hold.
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View productg40 indicates tight tolerance and surface quality suitable for many rolling element applications, as stated on the product page. it sits tighter than g100 and looser than g10, so it is a general-purpose precision band rather than a spindle-grade one.
the product lists aisi 52100 / suj2 / gcr15 / 100cr6 — four designations for the same high-carbon chromium bearing steel — hardened to hrc60-66, with a grinding surface and din / aisi / gb standards. certification is listed as iso and rohs.
the range covers 9.0mm to 15.875mm, with 15.875mm equal to 5/8 inch. for larger diameters in the same chrome steel family, the supplier also lists a gcr15 range at 31mm, 45mm, 46mm and 47mm.
the sales unit is a multiple of 20. each batch is packed in a cardboard box on a pallet measuring 31 × 21 × 12 cm, with a stated total batch weight of 20.500 kg.
the page lists applicable industries as building materials stores, production workshops, repair shops, energy and mining companies, and hardware accessories, and positions the product for bearing production, repair inventory, distributor stock and general industrial assembly programs that need material traceability and repeatable mechanical performance.
use the get a quote action on the product page or the contact us page, and include the diameters you need, the grade on your drawing and your planned order quantity so the reply covers availability, lead time and price in one go.