Engineering Calculators

Dowel pin: press + slip hole sizing Beta

v1.1 · Start from the pin tolerance and your desired fit windows. Size one press-fit hole and one removable slip-fit hole independently.

DIAMETRAL / EXACT INWARD ROUNDING

Editable 6 mm starting example. All inputs can be adjusted.

Starting pin: 6.000 mm nominal with +0.004/+0.012 mm signed deviations, from the MISUMI 6 mm MSTM m6 example. Press interference 0.005–0.025 mm and slip clearance 0.010–0.030 mm are illustrative choices, not supplier recommendations or universal average fits. Changing nominal does not select a new supplier tolerance.

Length unitPin input modePin nominal (reference) mm

Signed lower deviation mmSigned upper deviation mm

All sizes and fits are diametral. Enter signed deviations from nominal, or the actual lower/upper pin limits. Decimal values and exact fractions (such as 1/64) are accepted. Unit switching converts values exactly; fractions may appear for non-terminating decimals.

Choose your target fit windows

Choose values for your application. No universal interference or clearance is assumed. Strictly positive minima avoid line-to-line contact dimensionally.

Minimum press interference mmMaximum press interference mmMinimum slip clearance mmMaximum slip clearance mmOutput increment (optional) mm

An output increment rounds each lower hole limit up and each upper limit down. Results are checked again at that precision. Blank leaves the exact algebraic result.

Inverse-sizing derivation & scope

For actual pin limits Pmin–Pmax and desired interference Imin–Imax, the widest guaranteed press-hole band is [Pmax − Imax, Pmin − Imin]. For desired clearance Cmin–Cmax, the widest guaranteed slip-hole band is [Pmax + Cmin, Pmin + Cmax]. If a fit window is narrower than pin variation, that side is infeasible. An equal-width window leaves zero hole manufacturing tolerance.

The intended arrangement keeps the pin in the press-fit member and allows removal of the slip-fit member dimensionally, subject to practical factors. Zero minimum interference or clearance permits line-to-line contact and does not guarantee retention or free sliding.

Results use exact decimal/fraction arithmetic. With a chosen increment, lower hole limits round up and upper limits round down. Achieved fit extremes are recomputed from those shown limits. If no interval remains, only the exact pre-rounding result is shown and the chosen precision is flagged as incompatible. Midpoint ± half-width is exact, without display rounding.

No ISO fit class is selected. Background: MISUMI: shaft and hole clearance/interference fits. The sizing here is algebraic inverse sizing, not a table lookup.

Check existing hole and pin limits (original calculator)

Derivation & scope

Minimum clearance = smallest hole − largest pin. Maximum clearance = largest hole − smallest pin. A range crossing zero is a transition fit; either clearance or interference may occur. A zero endpoint allows line-to-line contact.

This checks size limits only. It does not calculate installation force or retention, and does not assess surface finish, form, alignment, material, temperature, coatings or assembly method. Enter drawing or measured limits; no ISO/ASME fit tables are reproduced.

One-dimensional tolerance stack Beta

Build a signed chain from absolute lower and upper limits. Subtracted dimensions reverse the contribution limits.

WORST CASE + OPTIONAL RSS

Length unit

All terms share this unit. Use + for dimensions along the chain and − for opposing dimensions. Labels are for your reference.

Term	Sign	Minimum	Maximum	Edit

Show optional RSS estimate (each interval assumed midpoint-centred, independent, normal and ±3σ)

Derivation & statistical assumptions

For + terms, contribution = [minimum, maximum]. For − terms, contribution = [−maximum, −minimum]. Sum all lower contributions for the worst-case minimum and all upper contributions for the worst-case maximum.

Optional RSS uses each interval midpoint as its assumed mean, with half-width = 3σ. Chain centre = sum of signed midpoints. The chain's estimated ±3σ half-width = √Σ(half-width²). This is a model assumption, not a measured distribution. Correlated terms, process shifts and non-normal data can invalidate it. Asymmetric drawing tolerances need not have a process mean at the interval midpoint.

Worst-case bounds describe this one-dimensional size chain. Neither result establishes functional interchangeability, geometric conformity or assembly performance.

OEE & production losses Beta

Evaluate one production period at one ideal cycle time. Separate scheduled time, runtime, speed loss and first-pass quality.

SINGLE-PERIOD CALCULATOR

Derivation, interpretation & sources

Planned production = period − excluded time. Runtime = planned production − downtime. First-pass good = total − first-pass non-good. Availability = runtime / planned production. Performance = ideal cycle seconds × total / (runtime minutes × 60). Quality = first-pass good / total. OEE = availability × performance × quality = ideal cycle seconds × first-pass good / (planned production minutes × 60).

No scheduled production yields N/A. With scheduled time and zero output, OEE is 0%; factors with zero denominators remain N/A. Missing inputs are not treated as zero. Performance above 100% is shown with a data-quality warning; check the ideal cycle and count/time boundaries.

For repeated periods, recompute from consistent raw measures. Do not average OEE percentages. Mixed ideal cycle times require a separate, explicitly weighted method. This is a local calculator; ongoing production tracking is a separate system.

References: Vorne: calculating OEE · OEE factors.