If you spec 8620 Round Bar for camshafts or gears, it has probably crossed your desk. It carburizes predictably, machines cleanly before heat treatment, and delivers surface hardness over a tough core. That combination is exactly what cam lobes and gear teeth need to survive real operating conditions.
At Precision Ground Bars, we’ve supplied 8620 round bar to automotive and fabricated metal manufacturers across the Chicago area since 1970. We stock it alongside a full alloy steel lineup and back it with centerless grinding, bar straightening, and cutting services.
Why 8620 Is the Right Carburizing Grade for Camshaft and Gear Work
8620 is an alloy carburizing steel that develops a hard outer case and a soft, ductile core when subjected to thermal heating. The surface resists wear and contact stress. The core absorbs shock without cracking. No through hardened grade gives you both in the same bar.
The chromium in 8620 ensures excellent hardness penetration, so the case reaches useful depth. Molybdenum imparts high strength and uniform hardness, keeping core properties consistent across a full production run. You also get excellent toughness, good wear resistance, and ductility built into the same grade.
Case-and-Core Performance for Gear Teeth and Cam Lobes
Most gear and camshaft failures start at the surface. The lobe face or tooth wears out long before the core gives way. 8620 solves that problem directly. The carburized case protects the surface while the ductile core handles the shock load underneath.
That profile is why 8620 stays on gear and camshaft drawings across automotive, screw machine, and fabricated metal manufacturing. You can machine blanks cleanly before carburizing, then rely on the predictable case response after heat treatment without fighting distortion.
Temperature Resistance That Matters in Engine and Industrial Applications
Camshafts run near the engine heat. Industrial gearboxes operate under sustained load at elevated temperatures. 8620 offers excellent resistance to creep at temperatures as high as 1,000°F, which keeps components dimensionally stable under those conditions.
Its good scaling properties also make it suitable as forging stock when your process calls for it. For production shops designing parts for long service life in thermally loaded environments, those properties reduce risk without requiring an exotic or expensive grade change.
Where 8620 Gets Specified Across the Chicago Manufacturing Region
We see 8620 on drawings for crankshafts, gears, spindles, axles, and steering shafts regularly. Automotive manufacturers across Chicago, Orland Park, Oak Lawn, and Tinley Park pull from this grade for both passenger car and heavy-duty truck components.
Screw machine shops running gear blanks and camshaft slugs count on a consistent alloy bar that performs the same way every time. 8620 delivers that. When your operation runs at volume, bar-to-bar consistency in the incoming material is not a small detail.
Grinding and Finishing Services We Offer for 8620 Bar Stock
Bar stock that arrives out of round or off-diameter creates problems before you cut the first blank. Our centerless grinding service achieves tight tolerance, precision roundness, and a clean surface finish on 8620 bar stock. Consistent incoming bar means fewer setup adjustments and less scrap on your floor.
Precision Ground Bars also offers OD grinding for applications where the starting diameter needs to be held tighter than the standard mill finish provides. That matters when your turning operation feeds bar diameter directly into your part tolerances before the carburizing step.
Bar Straightening to Remove Bow Before Machining
Alloy bars can carry residual bow from the mill. On a camshaft blank, any bow in the incoming bar causes vibration and chatter during rough turning. Bar straightening is the first operation in bar finishing, returning bars to the correct shape before machining begins.
We offer both press straightening and precision straightening for bars that have picked up distortion from prior processing. Removing that bow early protects your tooling and keeps run-out under control through every subsequent operation.
Bar Stock Cutting to Your Exact Specified Lengths
We cut bar lengths to exact customer specifications. If your camshaft or gear production line requires blanks cut to a specific length, we handle that as part of the order. You receive material ready to load, not random lengths requiring an extra cutting step.
That reduces handling time on your end and keeps your production flow clean. Combined with centerless grinding and straightening, it means the bar arriving at your machine is already prepared for the first cut.
Ready to Source 8620 Round Bar for Your Application?
Precision Ground Bars stocks 8620 alongside 4130, 4140/4142, 41L42, 86L20, and Fatigueproof in standard and custom sizes. Our facility is at 8150 W 111th St, Palos Hills, IL, and we serve manufacturers across the Chicago area. We’re available Monday through Friday, 8 AM to 5 PM.
Submit a quote at precisiongroundbars.com/submit-a-quote, call toll-free at (800) 818-0822, or reach our local line at (708) 880-7277. Tell us your diameter, length, quantity, and any grinding or cutting requirements, and we’ll take it from there.
FAQs
Why choose 8620 over 4140 for camshaft applications?
8620 carburizes to give a hard case over a tough core. 4140 is through-hardened. Cam lobes need case hardening, making 8620 the right choice.
What grinding services do you offer for 8620 bar?
We offer centerless grinding, OD grinding, bar straightening, and bar stock cutting to your exact specified lengths.
Do you carry other alloy grades alongside 8620?
Yes. Our alloy steel inventory includes 4130, 4140/4142, 41L42, 86L20, and Fatigueproof in standard and custom sizes.
How do I place an order for 8620 round bar? Submit a quote at precisiongroundbars.com/submit-a-quote or call (800) 818-0822, Monday through Friday, 8 AM to 5 PM.
