Knurlers held in via friction pins.

Scissors-type knurler. This type works very well.
All the pressure is in-between the cutters & it floats on the pivot.
Left, right & bottom views shown as mounted in a Phase2+ tool holder.
I modified the pivot bolt head & added a lock nut to it.

Knurling aluminum in the Jet BD-920N lathe.

A standard knurler with interchangeable cutters. Also holds a tool bit for facing cuts.
Really need a rigid machine & setup for this type of knurler since it exerts high side forces.

Clamping-type knurler. Good for light knurling in soft materials.
Scissors-type can exert higher pressures to form a true, high-grip, pyramidal pattern.

Replaced pivots with 10-24, " x " shoulder bolts with lock nuts
for added precision, strength & ease of knurl pair changes.
The bolt heads on the left had flats milled into them to engage the step to prevent rotation.

A knurler for the Taig Micro Lathe closely patterned after the Sherline design, but stronger.
Standard-sized knurls pivot on " diameter hardened dowel pins.
They are held in place by 10-24 set screws. The pin holes were precision reamed.
Knurl pockets (1" L x ⅜" W x 0.7" D) were made using a ⅜", 2-flute, carbide end mill.
Used the RF-25 mill with its DRO-350 tool diameter off-set feature
Two, -20 cap-head cross-bolts easily exert all the knurling force.
The two supports have keys that ride in a carriage T-slot.  10-32 threaded rods are used for the hold-down bolts.
First, finger tighten the hold-down bolts, adjust cross-bolts for desired knurl depth, then wrench tighten the hold-down bolts.
Turn the spindle by hand for smaller jobs & use the low, 525 RPM for larger jobs.
Put light pressure on the right to left carriage travel while knurling.