Custom Machined Flanges
Resolute Precision Manufacturing produces custom CNC machined flanges to drawing turned, faced, bored, and drilled to your specifications in steel, stainless, aluminum, and brass. Whether you need a simple pipe flange with a drilled bolt circle or a complex weld neck flange with precision bore and face tolerances, we produce it directly for your team with 24-hour quote response and ISO 9001 controlled quality. Request a QuoteTurning and Milling Combined for Complete Flanges
A precision flange requires both turning operations OD, bore, face and milling or drilling operations bolt holes, slots, and machined pockets. At Resolute Precision, flanges are produced on our CNC turning centers with live tooling that complete the turned OD, bore, and face in the same operation as the drilled bolt hole pattern and any milled features.
For larger flanges that exceed our bar-fed turning diameter, chucked turning combined with subsequent milling on our vertical machining centers produces flanges up to 25.5 inches in diameter with all features referenced from a single common datum.
Our Services
Critical Flange Dimensions and Tolerances
The dimensions that matter most on a precision flange are the face flatness and perpendicularity to the bore axis, the bore diameter and finish (which must match the mating pipe or fitting), the bolt hole circle diameter and angular spacing, and the overall thickness. Resolute Precision holds these dimensions to drawing specifications with CMM-verified inspection on first articles and spot checks throughout production runs.
Specifications
| Turning Capacity | OD up to 25.5″ diameter; bore sizes from small-bore to near-OD |
| Bolt Hole Patterns | Drilled with live tooling (smaller flanges) or machined on vertical mills (larger flanges) |
| Face Flatness | Turned and faced in the same setup; flatness to drawing specifications |
| Bore Finish | Bored or reamed to the specified diameter and surface finish |
| Standards | ASME B16.5, ASME B16.47, DIN, JIS, or customer-proprietary drawings |
| Metals | Carbon steel (A105, 1018), stainless steel (304/316/F316L), aluminum (6061), brass |
| Tolerance | OD/bore: ±0.001″ standard; flatness: 0.001″ per inch; bolt circle: ±0.002″ standard |
| Volume | Prototype to production |
| Certifications | ISO 9001:2015 |
Flange Applications From RPM
Custom machined flanges from Resolute Precision are used across a broad range of fluid, mechanical, and structural connection applications:
Pipe flanges — ASME B16.5 weld neck, slip-on, socket weld, and blind flanges in carbon and stainless steel
Hydraulic and pneumatic flanges — SAE 4-bolt and 2-bolt split flanges for high-pressure connections
Shaft flanges and couplings — precision turned flanges for shaft-to-shaft and shaft-to-housing connections
Instrument flanges — stainless flanges for pressure, temperature, and flow instrument connections
Industrial machinery mounting flanges — custom flanges for motor, gearbox, and actuator mounting
Marine hardware flanges — brass and stainless flanges for through-hull and sea-cock connections
Frequently Asked Questions
Can RPM produce ASME standard flanges?
Yes. We produce flanges to ASME B16.5, B16.47, B16.48, and other applicable standards. We work from your drawing that references the standard we machine to the dimensions and tolerances that drawing calls for.
What is the largest flange diameter RPM can produce?
Our turning centers handle chucked workpieces up to 25.5″ in diameter. For larger flanges, we can machine the critical ID, OD, and face features on a turning center and complete the bolt hole pattern on our vertical machining centers.
Can RPM supply flanges with material traceability?
Yes. We source materials with mill certifications and can provide certified material test reports (CMTR) with the delivery. For pressure-containing applications or regulated industries, material traceability documentation is available on request.
Does RPM offer flanges with surface treatment?
Yes. Through our outside coating and processing services, we coordinate passivation of stainless flanges, zinc or nickel plating of carbon steel flanges, and anodizing of aluminum flanges delivering fully finished parts from a single purchase order.