KEVOS® WORKOS · Engineering
Retention Method Selector
Which axial retention method suits this joint, and what will it cost over its life?
Screens up to three axial retention methods for a shaft or bore against load, speed, temperature and disassembly needs, then compares lifecycle cost, risks, assembly guidance and drawing requirements. Technical rejection always overrides cost.
Open the calculatorRuns in your browser. No account needed.
How this tool works
Inputs, units and where to find them
| Input | Unit | Typical source |
|---|---|---|
| Application | ||
| Retention location | choice | Design: whether the part is retained on a shaft or in a bore |
| Shaft or bore diameter | mm | Design drawing: nominal shaft or bore diameter (used to choose catalogue sizes) |
| Maximum axial load in service | N | Load calculation: maximum axial load including dynamic effects |
| Load character | choice | Load calculation or duty description |
| Rotational speed of the retained parts | rpm | Specification: maximum rotational speed of the retained parts |
| Maximum service temperature | °C | Specification: maximum service temperature at the joint |
| Disassembly requirement | choice | Maintenance concept: how often the joint must be taken apart |
| Required design factor (your approved value, 0 = not set) | × | Your design standard or company practice; the tool never assumes a value |
| Production and lifecycle | ||
| Annual production volume | units | Production forecast |
| Production life | years | Planned production life |
| Service disassemblies per unit over its life | times | Maintenance plan: disassemblies per unit over its service life |
| Loaded labour rate | $/hr | Loaded labour rate from finance |
| Candidate A | ||
| Candidate A method | choice | Candidate retention method to assess |
| Rated axial capacity (0 = not supplied) | N | Axial capacity for this exact size and material from the supplier datasheet, the standard, or your validated calculation or push-out test |
| Rated maximum speed (0 = not supplied) | rpm | Maximum speed for this size from the supplier catalogue (rings and clips) |
| Rated maximum temperature (0 = not supplied) | °C | Maximum service temperature from the datasheet (essential for adhesives) |
| Part or material cost | $/unit | Supplier quotation for the retaining part or compound per unit |
| Feature machining cost (groove, hole, thread, fit) | $/unit | Machining cost of the groove, cross-hole, thread or fit per unit (routing × rate or supplier) |
| Assembly time | s/unit | Time study or estimate for assembling one unit |
| One-off tooling and fixtures | $ | Quotations for applicators, press tools, staking tools or fixtures |
| Candidate B | ||
| Candidate B method | choice | Candidate retention method to assess |
| Rated axial capacity (0 = not supplied) | N | Axial capacity for this exact size and material from the supplier datasheet, the standard, or your validated calculation or push-out test |
| Rated maximum speed (0 = not supplied) | rpm | Maximum speed for this size from the supplier catalogue (rings and clips) |
| Rated maximum temperature (0 = not supplied) | °C | Maximum service temperature from the datasheet (essential for adhesives) |
| Part or material cost | $/unit | Supplier quotation for the retaining part or compound per unit |
| Feature machining cost (groove, hole, thread, fit) | $/unit | Machining cost of the groove, cross-hole, thread or fit per unit (routing × rate or supplier) |
| Assembly time | s/unit | Time study or estimate for assembling one unit |
| One-off tooling and fixtures | $ | Quotations for applicators, press tools, staking tools or fixtures |
| Candidate C | ||
| Candidate C method | choice | Candidate retention method to assess |
| Rated axial capacity (0 = not supplied) | N | Axial capacity for this exact size and material from the supplier datasheet, the standard, or your validated calculation or push-out test |
| Rated maximum speed (0 = not supplied) | rpm | Maximum speed for this size from the supplier catalogue (rings and clips) |
| Rated maximum temperature (0 = not supplied) | °C | Maximum service temperature from the datasheet (essential for adhesives) |
| Part or material cost | $/unit | Supplier quotation for the retaining part or compound per unit |
| Feature machining cost (groove, hole, thread, fit) | $/unit | Machining cost of the groove, cross-hole, thread or fit per unit (routing × rate or supplier) |
| Assembly time | s/unit | Time study or estimate for assembling one unit |
| One-off tooling and fixtures | $ | Quotations for applicators, press tools, staking tools or fixtures |
Method and formulas
- Each candidate is checked against: joint type, disassembly need, load character, capacity ÷ load against the required design factor, rated speed and rated temperature, plus method-specific evidence (calculated press-fit force, tested staking force).
- Any failed check rejects the candidate. Missing ratings, limits or design factor give VERIFY, never PASS.
- Unit cost = part + feature machining + assembly time × labour rate.
- Lifecycle cost = units produced over the life × (unit cost + service cost) + tooling; service cost = disassemblies × (2 × assembly labour + replacement part where the method needs one).
- Only PASS candidates can be recommended; among them, the lowest lifecycle cost is preferred.
- Costs rank candidates only when every candidate being ranked has costs entered; a blank cost is treated as unknown, never as zero.
Limitations
- The tool holds no catalogue dimensions, strength ratings, speed limits, safety factors or prices: all must come from you and your sources.
- Method rules reflect general engineering practice; they are not a substitute for the supplier’s data, the standard or a qualified design check.
- Shaft and housing stresses (grooves, cross-holes, threads, hoop stress) are not calculated here.
- Interference-fit holding force and staking force must be calculated or tested separately and entered as the rated capacity.
Typical uses
- Choosing how to retain a bearing, gear, pulley or bush axially
- Design-for-assembly and cost-down reviews
- Documenting why a retention method was chosen
Who it is for
- Mechanical design engineers
- Manufacturing and process engineers
- Engineering managers approving design changes
What you get
- RECOMMENDED method, ELIGIBLE: ENTER COSTS TO CHOOSE, VERIFICATION REQUIRED or NO ELIGIBLE METHOD
- Candidate comparison with technical status, capacity ratio and lifecycle cost
- Feasibility checks, risks, assembly guidance and drawing requirements
Interpreting the result
- A recommendation means every entered check passes; it is not design approval.
- VERIFICATION REQUIRED lists exactly which evidence is missing; close those items and re-run.
- Use the sensitivity table to see whether a modest load increase would reject the chosen method.
Before relying on the result
- Have a competent engineer check the selected method and its supporting calculations before release.
References
- DIN 471 and DIN 472, retaining rings for shafts and bores (confirm edition against your approved standards list)
- DIN 6799, retaining washers (E-clips) for shafts
- ISO 8750 (coiled) and ISO 8752 (slotted, heavy-duty) spring-type straight pins
- ISO 286-1 and ISO 286-2, ISO code system for tolerances on linear sizes (fits)
- ISO 898-1 and ISO 898-2, mechanical properties of fasteners (bolts and nuts)
- Budynas R. G. and Nisbett J. K., Shigley’s Mechanical Engineering Design (McGraw-Hill), press and shrink fits
WORKOS tools are screening and decision-support utilities. Verify important financial, engineering, safety, legal or operational decisions using appropriate professional standards and your organisation’s approved data.
