Check actuator clevis bracket pin fit, bearing pressure, material pair risk, machining route, and RFQ evidence before releasing a custom CNC yoke or pin bracket.
Updated July 13, 2026 | Fit + bearing pressure screen
First-pass tool
Screen pin fit direction, projected bearing pressure, and RFQ release risks before sending a custom actuator clevis bracket drawing.
Key conclusions
Evidence: A low-stress bracket can still fail if the pin is loose, coated after sizing, or forced through misaligned ears.
Action: Use the checker for first-pass fit and pressure direction, then freeze the pin and bore evidence together.
Evidence: Each ear can measure within diameter tolerance while the shared pin axis still binds during assembly.
Action: Call out datum references, Position tolerance, and same-setup boring or functional pin gaging for critical yokes.
Evidence: Bare aluminum against steel can wear quickly, and similar stainless sliding pairs can gall under load.
Action: Name bushing, coating, hardness split, lubrication, and after-finish bore requirements in the quote package.
Evidence: Suppliers cannot price inspection or avoid rework without the pin drawing, load case, finish stage, and acceptance method.
Action: Send STEP, 2D PDF, actuator datasheet, pin certificate or catalog drawing, material, finish, quantity, and inspection needs.
Method and limits
The tool estimates projected bearing pressure from pin diameter, lug thickness, lug count, and radial load. It also routes the fit class by duty target. It does not certify fatigue, weld strength, fasteners, actuator side-load limits, or real load spectra.
Treat a green result as RFQ readiness, not design approval. High-cycle, shock-loaded, welded, or safety-critical clevis brackets need engineering review with the real load case.
RFQ quick action
Send the actuator clevis bracket drawing package for DFM review before locking the bore tolerance, material pair, and machining route.
Calculation assumptions
The formulas below explain what the tool can and cannot support. Replace these screening assumptions with the customer drawing, load spectrum, pin certificate, material allowable, and inspection standard before approving production.
| Assumption | Tool value | Decision boundary |
|---|---|---|
| Projected bearing pressure | Radial load / (pin diameter x ear thickness x loaded ears) | Useful for RFQ triage when the load is mostly radial and shared across the lug faces. Off-axis load, shock, or one-sided loading needs engineering review. |
| Pressure planning limits | Steel 90 MPa; aluminum 35 MPa; stainless 70 MPa; steel with bronze bushing 50 MPa | Internal shop-screening bands used to flag quote risk. They are intentionally not presented as material code allowables or fatigue limits. |
| Fit direction | H7, H8, or H9/bushed clearance based on duty target and pin evidence | The released drawing should still cite buyer-controlled ISO/customer tolerance tables, pin tolerance, coating stage, and inspection method. |
| Outer lug width clue | Pin diameter + 2 x max(1.5 x pin diameter, pin diameter + 10 mm) | A packaging clue for early sourcing only. Compact clevis ears can be valid when backed by load analysis, material selection, and datum control. |
Fit selection
| Class | Use | Process | Limit |
|---|---|---|---|
| H7 | Servo or positioning clevises where backlash is more expensive than machining time. | Fine boring or reaming, controlled pin, CMM or functional gage. | High binding risk if the pin is commercial, coated after sizing, or the ears are not line-bored. |
| H8 | General industrial actuator clevis brackets and many CNC-machined yokes. | Reamed or interpolated bore with Ra 1.6 um target and pin tolerance review. | Still needs finish-stage control if plating, anodizing, paint, or bushing installation changes the bore. |
| H9 / bushed clearance | Agricultural, outdoor, dirty, or serviceable pivots where assembly clearance matters. | Looser bore, replaceable bushing, grease path, or hardened wear sleeve. | Backlash can be unacceptable for positioning systems unless the control loop tolerates it. |
Geometry routes
Best use: Light brackets, latch-style pivots, compact envelope.
Machining: Mill profile, drill/ream bore, inspect face-to-bore perpendicularity.
Release risk: Side-load and bending can be hidden if the mating fork carries uneven load.
Best use: Actuator rod-end or base-end pivots where the pin is supported on both sides.
Machining: Rough both ears, clamp from datums, line-bore both ears in one setup.
Release risk: Separate setups can create a pin axis mismatch even when both diameters pass.
Best use: Large envelopes, structural frames, low to medium precision pivots.
Machining: Weld, stress relieve when justified, finish datum faces, then bore the pin path.
Release risk: Weld pull and coating buildup can move the functional bore after rough sizing.
Best use: High cycle, field service, dirty environments, aluminum base material.
Machining: Machine housing bore, press or bond bushing, finish size the bushing ID when required.
Release risk: Press fit can shrink the bushing bore, so final ID inspection stage must be named.
Material decisions
| Material path | Best for | Watch item | RFQ note |
|---|---|---|---|
| Carbon steel / alloy steel | High load, shock, compact clevis ears, weldable brackets. | Corrosion protection, heat-treat distortion, and finish-stage bore size. | Send grade, heat-treat condition, coating, and whether the bore is final before or after finish. |
| 6061 / 7075 aluminum | Lightweight automation, robotics, and moderate load brackets. | Bore wear against steel pins and anodize buildup inside the clevis hole. The rotating steel pin can easily wear into the softer aluminum yoke. | Define bushing or hard-anodize plan, masked areas, and require plain washers (e.g. DIN 125) on both sides to prevent side-wear. |
| 304 / 316 stainless | Washdown, food equipment, marine, and corrosion-exposed machinery. | Work hardening, machining cost, and galling with similar stainless pins. | Specify pin grade or hardness split, lubricant, anti-galling coating, or bronze bushing. |
| Bronze bushing in steel bracket | Repeated pivoting, replaceable wear surface, easier field service. | Press-fit distortion, bushing retention, lubrication path, and spare-part control. | Send bushing material, installation method, final ID tolerance, and inspection plan. |
Risk matrix
Trigger: Drawing specifies H7/H8 bore but the mating clevis pin is a stock catalog item.
Impact: Backlash, binding, or inconsistent assembly from lot to lot.
Mitigation: Add pin shank tolerance, material, hardness, coating, and certificate requirement to the RFQ.
Trigger: Two ears are bored in separate setups or only checked with individual plug gages.
Impact: The pin passes each hole separately but binds through the assembled clevis.
Mitigation: Use a datum scheme, Position tolerance, same-setup line boring, and functional pin gage where needed.
Trigger: Peak radial load, shock factor, or one-sided ear loading is missing from the quote.
Impact: Hole elongation, lug cracking, bushing failure, or actuator-side load.
Mitigation: Quote static and dynamic load cases, duty cycle, shock factor, lubrication, and required safety target.
Trigger: Plating, anodizing, paint, or passivation is applied after the bore is sized.
Impact: Clearance disappears, or a previously acceptable pin fit becomes inconsistent.
Mitigation: State whether the tolerance applies before or after finish and require final gage check at that stage.
Trigger: Bare aluminum against steel or similar 304/316 stainless sliding contact under cyclic load.
Impact: Seized pin, fretting debris, higher backlash, or side-wear into the yoke.
Mitigation: Use a bushing, hardness split, anti-galling coating, lubricant path, or add plain washers (DIN 125) under the pin head/cotter to prevent yoke wear.
Trigger: Fabricated yoke is bored before welding, or final machining does not re-establish datums.
Impact: Pin path shifts after heat input and assembly stackup is no longer controlled.
Mitigation: Plan post-weld machining, stress relief when justified, and final inspection from functional datums.
Application routes
| Scenario | Likely route | Watch item | Best next step |
|---|---|---|---|
| Industrial linear actuator base clevis | Steel double-ear yoke with H8 bore and line-bored pin path. | Side-load from frame misalignment and finish-stage bore size. | Send actuator datasheet, pin drawing, frame datums, and coating requirement with the RFQ. |
| Robotics or servo positioning clevis | H7 bore, ground pin, controlled surface finish, and CMM report. | Backlash target can conflict with assembly tolerance stack. | Validate pin tolerance, position tolerance, and alignment features before cutting metal. |
| Agricultural or outdoor hydraulic linkage | Bushed steel bracket, grease path, looser serviceable clearance. | Contamination, impact load, corrosion, and field replacement. | Quote bushing material, lubrication feature, coating, and spare bushing strategy. |
| Washdown stainless actuator bracket | 304/316 bracket with dissimilar pin, bushing, or anti-galling strategy. | Stainless work hardening, galling, and cleanability around the yoke. | Define surface finish, passivation, pin hardness split, and lubricant limitations. |
| Hydraulic cylinder mounting clevis | Standardized bracket matching ISO 8132 medium/25 MPa series or ISO 8133 compact series dimensions. | Whether the buyer specifies plain-pin, spherical-bearing, or custom accessory hardware. | Quote exact dimensions to the standard and specify if the bearing is pre-installed or press-fit later. |
Visual reference
Use these examples to clarify envelope, pin axis, lug thickness, and machining-route expectations before quoting a clevis bracket.
Evidence and limitations
| Source | Date | Use | Limit |
|---|---|---|---|
| Internal DFM screening model | Assumptions documented July 12, 2026 | Supplies the checker planning bands: steel 90 MPa, aluminum 35 MPa, stainless 70 MPa, and bushed steel 50 MPa projected bearing pressure. | These are RFQ triage limits, not design allowables. Replace them with customer stress limits, fatigue review, FEA, and safety factors before production release. |
| ISO 286-1 tolerance system | Publisher page reviewed July 13, 2026 | Frames hole-basis tolerance language such as H7, H8, and H9 for bracket bores. | The checker uses screening bands only. Released drawings should cite the buyer-controlled ISO table or customer standard. |
| ISO 2341 clevis pins | Publisher page reviewed July 13, 2026 | Identifies the standard clevis-pin family and why pin data must be checked with the bracket bore. | Public metadata does not replace the purchased standard, supplier drawing, or pin certificate. |
| ISO 8132 hydraulic cylinder accessories | Publisher page reviewed July 13, 2026 | Identifies medium and 25 MPa single-rod cylinder accessory mounting dimensions, including straight or angled clevis brackets and pivot pin options. | ISO lists ISO/DIS 8132 under development. Confirm the buyer-controlled edition before release; pneumatic, electric, or custom actuators may not follow this family. |
| ISO 8133 compact cylinder accessories | Publisher page reviewed July 13, 2026 | Identifies compact series single-rod cylinder accessory mounting dimensions, including straight clevis brackets and spherical-eye clevis brackets. | ISO lists ISO/DIS 8133 under development. Confirm the buyer-controlled edition before release; pneumatic, electric, or custom actuators may not follow this family. |
| ASME Y14.5 GD&T | Publisher page reviewed July 13, 2026 | Supports datum, position, MMC, and drawing-interpretation language for double-ear alignment. | Use the drawing-controlled edition and qualified GD&T review for production release. |
| ASTM G98-23 galling resistance | Publisher page reviewed July 13, 2026 | Frames sliding material-pair galling as a screening and ranking issue. | Lubrication, hardness, stiffness, pressure, and environment still need application validation. |
| Customer drawing and actuator datasheet | Project-specific evidence required before RFQ award | Controls load case, stroke envelope, pin size, finish stage, material, and inspection acceptance. | No public guide can certify a clevis bracket without the actual load path and mating parts. |
RFQ checklist
Controls bore diameter, pin-axis position, face flatness, material, finish, and acceptance criteria.
Minimum: PDF drawing plus STEP model; name critical-to-function dimensions.
The pin often dominates backlash and can make a tight bore class meaningless.
Minimum: Pin nominal diameter, tolerance, material, hardness, coating, and certificate or catalog drawing.
Bearing pressure and lug geometry depend on peak radial load, shock, cycle rate, and lubrication.
Minimum: Static load, dynamic load, duty cycle, environment, and target safety margin.
Coating or bushing installation can change the final bore and pin clearance.
Minimum: Material grade, heat treatment, finish, masked features, and before/after finish tolerance rule.
A low unit price can hide missing proof for the features that decide assembly success.
Minimum: First article, material cert, bore report, functional pin gage, CMM report when required.
Related decision paths
Use when the main question is H7/H8/H9 pin fit, coating stage, or backlash versus binding.
Use when the bracket adapts bolt patterns or frame interfaces rather than acting as a pin yoke.
Use when the critical feature is a bearing seat, not a clevis pin bore.
Check Ra targets, coating stage, and sliding-contact finish decisions for bracket bores.
Review CNC machining and inspection support for precision bracket bores and datum control.
Compare broader actuator mounting bracket capabilities and product examples.
Buyer questions
Send the STEP file, 2D drawing, mating pin details, load case, material, finish, quantity, and inspection evidence required. We will review manufacturability and RFQ risk before quoting.
