9 inputs determine the right cylinder.

A distributor-facing pre-quote checklist. If the customer answers most of these at the first call, the second call is the quote.

1. 01
   What's the stroke length the machine cycle actually needs?

   Stroke is the first sort. Under ~100 mm in tight envelope → compact. Standard stroke (100-600 mm) → ISO 15552 or NFPA tie-rod. 500-2,500 mm in a short installed length → rodless. Get the stroke before talking brand.
2. 02
   What bore size does the load require?

   Bore + supply pressure = available force. Force = π × (bore/2)² × PSI × 0.9 for a typical rod cylinder. A 2" bore at 100 PSI gives ~280 lbf push; a 3" bore at the same pressure gives ~640 lbf. Don't undersize — friction and side-load eat 10-20% of the calculated force in real installs.
3. 03
   What's the mounting style the machine bracket is built for?

   Foot mount, flange, clevis, trunnion, pivot — the bracket dictates the cylinder, not the other way around. If the customer is replacing an existing cylinder, photograph the mounting before quoting. Wrong mounting style is the #1 returns reason on cylinder orders.
4. 04
   Is there side-load on the rod, or pure axial push-pull?

   Tie-rod and compact cylinders are built for axial loads only. Any meaningful side-load → heavy-duty cast (SMC CA2) or an external linear-bearing guide. Side-loading a standard cylinder bends the rod within months and the seal fails right after.
5. 05
   Does the rod need to maintain angular orientation through the stroke?

   Standard round-rod cylinders allow free rotation of the rod under load — for most jobs that's fine. If the tool, jig, or end-effector can't be allowed to spin, spec a non-rotating cylinder (SMC MB) or add external anti-rotation hardware.
6. 06
   Is this cylinder going into a PLC-controlled cycle that needs position feedback?

   If yes, every cylinder gets a position sensor (or two — end of retract + end of extend). SMC cylinders ship with a magnetic piston ring as standard; the sensor snaps into the body groove and wires direct to PLC input. Reed switch under 2 Hz; solid-state above 2 Hz.
7. 07
   Is this a new install, or a replacement on an existing North American machine?

   Replacement on an existing Parker, Bimba, or Numatics installation defaults to NFPA tie-rod for drop-in dimensional match. New install with no legacy constraint → ISO 15552 (AIGNEP for value, SMC for spec). Don't quote ISO as a Parker replacement; the bolt pattern won't line up.
8. 08
   What's the cycle rate — strokes per minute under typical duty?

   Cycle rate drives seal life and sensor selection. High-cycle duty (above 60 strokes/min) wants premium seal kits and solid-state position sensors, not reed switches. Quote a rebuild kit as a preventive spare on any cylinder cycling more than 30/min.
9. 09
   Is the cylinder in a washdown, food-contact, or chemically aggressive environment?

   Standard NBR seals don't tolerate FDA-grade lubricants or aggressive washdown chemistry. Food-contact or harsh-environment installs need FKM or food-grade seal packs and often stainless rod plating. Spec the rebuild kit in matching seal material at the same time as the cylinder.