Precision ground bars for CNC machining, Swiss machining, shafting and industrial components. Mozaic Precision Metals supplies finished precision ground round bar stock and can process customer-owned bars to specified outside diameters, lengths and surface requirements. We review the exact grade, condition, starting size, finished tolerance and quantity before quoting.
Precision Ground Round Bar Stock: Supply and Finishing
A precision ground bar is round stock finished to a controlled outside diameter by grinding. Buyers use precision ground steel bars and other alloys when consistent bar diameter and surface condition help machining, feeding and fit-up. Grinding does not, by itself, establish the material grade, straightness, hardness or final component performance; those requirements belong on the drawing or purchase order.
Need a job shop to grind material you already have? See our dedicated centerless grinding services page. For supply of finished round bars, start here.
Materials Available for Ground Bar Inquiries
| Material family | Examples | Buyer considerations |
|---|---|---|
| Stainless steel | 303, 304, 316, 17-4 PH | Corrosion exposure, machining grade, condition, traceability |
| Carbon and alloy steel | 1018, 1045, 4140, 4340 | Cold-drawn versus heat-treated condition, dimensional allowance |
| Tool steel | A2, D2, H13 | Machining versus hardened condition, finish grinding allowance |
| Nickel and specialty alloys | Inconel 718, Monel 400 | Exact UNS/AMS standard, heat treatment, inspection and availability |
| Other metals | Aluminum and copper-based alloys by inquiry | Machining behavior, burr control, surface protection and finish |
These are examples, not a promise that every grade or size is in inventory. Mozaic can quote material supply plus grinding or customer-supplied material processing.
Specify Diameter, Straightness and Surface Finish Separately
When requesting ground round bar stock, state the finished nominal OD with its actual plus/minus tolerance or upper/lower limits. Define straightness by a measurable method and support span; straightness is not the same as total indicated runout on an unsupported setup. Roundness, surface roughness and length are separate acceptance characteristics.
- Outside diameter: required finished diameter, tolerance, unit of measure and measurement points.
- Surface finish: Ra or RMS and the specified maximum, if relevant to machining, seals or bearings.
- Bar length: full-length stock or cut-to-length pieces, including end facing allowance.
- Material: grade, condition, applicable ASTM/AMS/other standard, and mill test report needs.
- Quantity: number of bars or pounds, releases, packaging and delivery timing.
Our broader bar-processing capability covers a range of small to large diameters and long bars, but each size and tolerance is assessed against the alloy, condition, straightness and process route. Do not assume that one advertised minimum tolerance is available at every diameter or bar length.
Ground Bar Stock for Shafts, Pins and Bearing Applications
Precision ground round bars are commonly used as incoming stock for shafting, pins, rollers, bushings and Swiss machining. If your purchasing requirement is more specific, compare our bearing shaft quality bar, pump shaft quality stainless bar, and turned, ground and polished (TG&P) bar supply pages. Each targets a different application or processing route.
Bar Finishing, Straightening, Cutting and Packaging
Mozaic can coordinate bar straightening, polishing, saw cutting, chamfering and protective bar packaging with your ground bar order. We are ISO 9001:2015 certified; inspection and material documentation are planned around the actual purchase-order requirements.
Request a Precision Ground Bar Quote
Send your grade, original and finished diameter, OD tolerance, condition, lengths, surface/straightness requirements, quantity and delivery needs. Request a quote or email sales@mozaicprecision.com (phone 847-637-8379). We will confirm suitable material and processing options for the job.
Ground Bar Stock: What to Expect from an Actual Grinding Shop
Mozaic operates Cincinnati centerless grinding equipment and coordinates two-roll and press straightening, polishing, saw cutting and bar packaging. This lets buyers discuss source material and the required finished dimensions with one processing team instead of separately arranging each operation. Material may be sourced by Mozaic or sent in by the customer.
Bar Size and Production Planning
Our overall bar-processing scope includes approximately 0.060–8.000 inch outside diameter and 3–24 foot stock lengths, depending on the material and process. These are not universal thru-feed grinding limits: the allowable diameter, part geometry, finished straightness and wheel setup must be confirmed for each order. If you have a long or oversized shaft, send the drawing before assuming it fits a standard centerless setup.
Information That Helps Us Quote Faster
Example request: “17-4 PH stainless, Condition H1150, starting OD 0.630 inch, finished OD 0.6250 inch with upper and lower limits per drawing, 12-foot bars, 100 pieces, mill certificates required.” Include straightness, surface finish and delivery requirements as separate line items. This illustrates how to format an inquiry, not an offer of a particular tolerance or material inventory.
Customers preparing Swiss-lathe feedstock should also specify the bar feeder/guide bushing requirements and packaging limitations. Ready-to-machine bar suitability is determined by the exact machine and part, not the grade name alone.