Two Japanese lever brands turn up in almost every fightstick and almost every panel swap: Sanwa and Seimitsu. They mount in the same hole, they take the same ball tops, and they cost within a few dollars of each other. People still argue about them constantly, which is a good sign that the difference is real and a bad sign that it is easy to describe.

Here is what actually changes when you swap one for the other, and what does not change at all.

The two measurements that matter

Every lever has two distances, and confusing them is the source of most of the bad advice on this subject.

  • Engage distance is how far the shaft travels before a switch closes and the game registers a direction. It is set by how the lever is built - the actuator, the switch position, the pivot - and you cannot change it by changing the gate.
  • Throw distance is how far the shaft can travel in total before it hits the restrictor. This one is set by the gate, and swapping the gate is a two-minute job.

Almost everyone who says "I put an octagonal gate on and the engage got better" has changed the throw and the guidance, not the engage. That is still a real improvement - it is just a different one, and knowing which is which tells you whether you need a new gate or a new lever.

Sanwa: the default, and why

The Sanwa JLF is the lever most people mean when they say "Japanese stick". It ships in a large share of ready-made sticks and it is what most panel diagrams are drawn around. Its reputation is for a light spring and generously spaced engages: the directions come in early and the lever offers very little resistance on the way.

That combination is why the JLF feels the way it does. There is not much tactile signal at the moment a direction registers, so you learn the stick by position rather than by feel. Players who like it describe it as fast and effortless. Players who do not describe it as vague, floaty, or - the word that comes up most - loose.

Sanwa levers ship with a square gate. Circular, octagonal and bar-shaped gates are all available separately, and a gate swap is the cheapest meaningful change you can make to any lever.

Seimitsu: the same mount, a different hand feel

Seimitsu levers mount in the same panel hole and take the same tops, but they are tuned differently. The LS-32 is the direct comparison to a JLF: a stiffer spring and moderate engage distances, which together produce a much more defined moment of activation. You can feel the direction go in. For anything that rewards precise single inputs - maze games, shooters, anything where an accidental diagonal costs you a life - that feedback is worth a lot.

Two other Seimitsu levers come up often enough to be worth naming:

  • LS-40 - very short engage distances. The quickest lever of the group to register, and a common choice for shoot-'em-ups. It shares mounting plates and springs with the LS-32, so if you have one you can experiment cheaply.
  • LS-56 - stiffer again. The lever people move to when the LS-32 still feels light.

There is one detail here that matters more than any of the feel arguments, and it is covered in the 4-way guide below: Seimitsu levers - the LS-56 aside - ship with square, plus-shaped and bar-shaped gates in the box. A plus-shaped gate is a true 4-way restrictor. That means a Seimitsu lever arrives able to be converted to 4-way for free, where a Sanwa needs a part ordered separately.

Why an American stick feels like a different category

If your reference point is a real cabinet from a North American arcade rather than a Japanese candy cab, none of the above will describe what you remember. Happ and IL levers are built to a different brief, and the numbers are not close:

  • Body depth - a Happ or IL lever is about 2-1/4 inches deep. A Sanwa or Seimitsu is about 1-1/2 inches. This is a clearance question before it is a preference question.
  • Springs - American levers use large, strong springs. Japanese levers use smaller springs of varying strength. Even a stiff LS-56 is not in the same weight class.
  • Panel hole - American levers go in a 1-1/8 inch hole and mount 1/3 to 2/3 of an inch below the panel. Japanese levers go in a 24mm hole with 23-24mm of shaft standing above it, on a 1.6mm plate.

That last point is the one that ends most cross-brand swaps: the holes are different sizes. Going from American to Japanese means a mounting plate or a new panel. Going the other way means enlarging holes you cannot un-enlarge.

What actually carries over between the two Japanese brands

More than people expect, which is what makes experimenting cheap:

  • Ball tops and bat tops interchange across every Sanwa and Seimitsu lever. The one exception is the JLW-U, which needs an adapter for 40mm tops.
  • Microswitches are largely a commodity. Standard microswitches share measurements across brands, so Cherry, Sanwa and Omron switches are generally interchangeable.
  • Buttons share a 30mm standard hole (24mm for the small ones), so Sanwa and Seimitsu buttons drop into the same panel. Their switches can be swapped between button bodies too, which is the cheapest way to change button tension without buying new buttons.

What does not reliably carry over is the mounting plate. Plan on checking the plate before ordering a lever, not after.

Wiring: check the terminals before you order

The single most common ordering mistake in a panel swap is the terminal size. Sanwa and Seimitsu parts use .110 inch terminals. Happ and IL parts use .187 inch. A harness built for one will not fit the other, and this is discovered at the worst possible moment - panel off, everything else installed.

So which one

Ignore the brand loyalty. The question is what feedback you want at the moment a direction registers.

  • You want the lever to disappear - fast, light, no resistance, position over feel: Sanwa JLF.
  • You want to feel each input land - stiffer spring, defined engage, fewer accidental diagonals: Seimitsu LS-32.
  • You want the fastest possible registration, usually for shooters: Seimitsu LS-40.
  • You want what a 1982 cabinet felt like: an American lever, and a panel built for one - not a Japanese panel with an adapter.

And before you buy any lever at all: swap the gate on the one you own. It costs a fraction as much, takes two minutes, and changes the throw, which is often the thing that was actually bothering you. If it is not, you will at least know that the problem is the engage - and that is the part you have to change the lever to fix.

Levers, gates, buttons and encoders are in Controls & Parts, each with the hole size and terminal size on the spec sheet.