For an ISO 15552 round-body cylinder, the datasheet fields that drive every downstream calculation are bore (mm), stroke (mm), and piston-rod diameter (mm), with the ratio between rod and bore typically 0.30–0.60 for double-acting designs [S3].
Vendors publish these in three places on a cut sheet: the model-code key (e.g. 50/100-25 = 50 mm bore, 100 mm stroke, 25 mm rod), the dimensional drawing (letters A, B, KK, C, L), and the standard-stroke table, which on ISO 15552 lists 25, 50, 80, 100, 125, 160, 200, 250, 320, 400, 500 mm up to 2000 mm [S3][S4].
What each field means and how it is measured
Bore is the internal cylinder-tube diameter; on ISO 6432 mini-cylinders it runs 8, 10, 12, 16, 20, 25 mm, on ISO 15552 it runs 32, 40, 50, 63, 80, 100, 125 mm, and on NFPA/tie-rod heavy-duty builds it scales 1-1/2" through 14" (about 40–360 mm) [S4][S8].
Stroke is the usable piston travel, measured between the two end-of-stroke positions with the rod fully retracted and fully extended; standard-stroke catalogs quote integer millimetres with a published tolerance of +1/-0 mm at standard length, widening on long-stroke builds where thermal growth and rod deflection matter more [S3][S4].
Rod diameter (the "KK" dimension on imperial datasheets) is the polished, chrome-plated shaft diameter at the gland/seal; it is chosen together with stroke because rod-buckling under compression scales with the Euler term (L/k) squared, which is why catalog rod diameters grow faster than bore on long-stroke models [S5][S7].
Standard stroke tables and how to read them
SMC's Series MB lists standard strokes of 50, 100, 150, 200, 300, 400, 500 mm on bores 32–100 mm, and 25, 75, 125, 175, 250, 350, 450, 600, 700, 800, 900, 1000 mm on bore 125 mm, with the "long stroke" option taking bore 32–100 above the 500 mm mark [S4].
DADCO's HP series (nitrogen, not air, but datasheet format is identical) goes 32–100 mm bore with standard strokes up to 200 mm, illustrating the same integer-mm pattern that makes stocked catalogue conversions straightforward [S1].
On NFPA tie-rod cylinders the table is grouped by bore in inches: 2" bore lists 1, 2, 3, 4, 5, 6, 8, 10, 12, 14, 16, 18, 20, 24" strokes, while 8" bore lists 1, 2, 3, 4, 5, 6, 8, 10, 12, 16, 20, 24, 30, 36, 40, 48", with the same +1/-0 mm-equivalent imperial tolerance applied at the standard length [S3][S8].
Selecting rod diameter from bore and stroke
The two design constraints on rod diameter are (1) tensile/compressive stress at peak load and (2) Euler buckling on the extended stroke; for a 50 mm bore / 500 mm stroke cylinder, datasheets commonly show 20 mm rod, whereas a 100 mm bore / 1000 mm stroke build jumps to 30 or 35 mm rod, and an "oversized rod" option on the SMC MB series raises rod diameter by one ISO step (e.g. 50 mm bore with 25 mm rod instead of the standard 20 mm) for high-bending or high-side-load applications [S4][S7].
Peninsular's selection example uses a 1-3/8" rod (about 35 mm) on a 3" bore (about 75 mm) cylinder rated to push and pull a 545 lb load with line pressure at 70% of the rated value, which is the rule-of-thumb derate most catalogue push/pull tables apply when line pressure cannot be guaranteed at the cylinder port [S7].
For a related angle on sizing the upstream supply side, the datasheet parameters that surround bore and stroke (port size, cushion volume, air consumption per stroke) are mapped in Pneumatic Actuator Datasheet Parameters: Air Supply and Torque Sizing, which uses the same bore/rod numbers to size the air service unit.
Force, volume, and cushion derived from the three fields
Push (cap-end) force = piston area × working pressure = (π/4) × bore² × P; pull (rod-end) force subtracts rod area, so a 63 mm bore / 20 mm rod cylinder at 6 bar gives about 1873 N push and 1685 N pull, a 10% loss that datasheets tabulate as "theoretical" force and that pneumatic engineers further derate by 0.5 for cushions, seals, and rod seal friction [S5][S9].
Air consumption per stroke is (cap-end area + rod-end area) × stroke × cycle factor; Norgren's NFPA datasheet gives the formula straight on the spec page as "Cap End Cylinder Bore Area × Stroke" and "Head End Cylinder Bore Area – (Piston Rod Area) × Stroke", so the same three numbers feed both the force table and the SCFM/cycle table without any extra input [S8].
Cushion length is a function of bore and stroke (typically 0.2–0.4 × bore for fixed-cushion designs, longer for adjustable-cushion on heavy-duty tie-rod units), and the cushion needle-valve setting is a separate datasheet field, not derived from the three geometry fields alone [S2][S3].
Reading model codes, double-rod, and non-rotating variants
Parker's "How to Order" key for Series 2A/2AN (HY08-0910-1/NA) is a worked example of how bore, stroke, and rod diameter are encoded: bore is the first numeric field (1-1/2" through 14"), stroke is the second numeric field in inches, and rod diameter is selected from a separate rod-oversize code, so any old catalogue like HY08-0910-1/NA still decodes correctly against 2026 shipments because the code structure has not changed [S2].
Double-rod (through-rod) and non-rotating-rod variants add a fourth geometry field on the datasheet: the second rod diameter, which is by default the same as the first, and the non-rotating-rod tolerance (SMC's MBK series quotes anti-rotation accuracy of ±0.5° to ±1° depending on bore, achieved by an integrated guide rod parallel to the piston rod) [S4].
For readers tracking the upstream materials picture, Grey Cast Iron Price Hikes Track Scrap Steel, Energy, and Freight, Not Hot-Rolled Coil explains why NFPA-style cast-iron end-cap pricing on heavy-duty cylinders moves on a different index than the chrome-plated steel rod stock, and that rod price delta is what drives the "oversize rod" option premium on long quotes.
Limits, tolerances, and common datasheet traps
Standard-stroke tolerance of +1/-0 mm (or +1/16"/-0" on imperial) applies only at the standard length; custom-stroke tolerances on long-stroke cylinders widen to +2/-0 mm above 1000 mm because rod sag and seal stack-up tolerance compound, and suppliers will not hold the standard tolerance on non-stock lengths [S3][S4].
Two datasheet traps repeat: (1) quoting the "bore" as the nominal tube ID and then computing force off the actual measured ID, which on tie-rod NFPA cylinders can be 0.5–1.5 mm under nominal due to honing, and (2) treating single-rod and double-rod models as interchangeable in the push/pull table when the double-rod version has equal-area cap and head ends and so produces the same push and pull force rather than the asymmetric pair of a single-rod unit [S5][S8].
Temperature and seal-material ratings are not on the geometry fields, but they decide which bore/stroke/rod combination a datasheet will warranty; SMC's MB series offers a heat-resistant variant rated −10 °C to 150 °C and a separate variant rated −10 °C to 110 °C, both of which impose a different gland seal stack than the standard NBR unit, so the same bore/stroke/rod geometry can carry two different part numbers and two different pressure ratings [S4].
Comparison: bore/rod ratio at common ISO 15552 sizes
The table below is a typical datasheet pattern for ISO 15552 double-acting cylinders, with theoretical push and pull force at 6 bar (0.6 MPa) gauge pressure; the rod is the standard (non-oversized) diameter published by major European and Japanese vendors [S3][S4][S5].
Bore 32 mm / rod 12 mm: push 483 N, pull 415 N, push/pull ratio 0.86, typical use clamping, small indexing, and light diverters. Bore 50 mm / rod 20 mm: push 1178 N, pull 990 N, push/pull ratio 0.84, typical use packaging gates and small press fit. Bore 80 mm / rod 25 mm: push 3016 N, pull 2722 N, push/pull ratio 0.90, typical use horizontal transfer and small press. Bore 100 mm / rod 30 mm: push 4712 N, pull 4288 N, push/pull ratio 0.91, typical use press, gate, and large transfer. Bore 125 mm / rod 32 mm: push 7363 N, pull 6881 N, push/pull ratio 0.93, typical use heavy stamping and large gate.
The push/pull ratio column is the field to watch: a 32 mm bore with a 12 mm rod loses 14% of force on the retract stroke, while a 125 mm bore with a 32 mm rod loses only 7%, which is why high-bore datasheets can publish nearly symmetric push/pull tables while low-bore datasheets cannot [S5][S9].
For a worked walk-through of how the same three fields are then checked against the cylinder's catalog buckling chart, the encyclopedia entry on pneumatic cylinder lays out the same bore/stroke/rod calculation in a maintenance-engineer context.
Sourcing signals to track in the next sourcing cycle
Two trackable signals: (1) long-stroke NFPA tie-rod lead times in the 8–14" bore band, where Parker 2A/2AN deliveries have stretched on the 200–1000 mm stroke range through 2025–2026, and (2) the increasing prevalence of "oversize rod" as a stocked option on ISO 15552 datasheets, which lets buyers skip the long lead time of a custom build when the application only needs a stiffer rod rather than a larger bore [S2][S3][S4].
The underlying component specifications are covered under wire rod, and checking and testing apparatus.