Crankshaft Thread Size Chart

This chart should be helpful when selecting spinners, spinner adapter nuts and hub nuts for your aircraft.

 Manufacturer Engine Designation Thread Size
 ASP .21 ABC - .46 ABC 1/4" - 28
 ASP .61 all models, .75 ABC, .91 ABC,
.65 4-C, .80 4-C
5/16" - 24
 Enya SS.25, SS.25BB, SS.30, SS.30BB, .35X, SS.40, SS40BB, SS.45 Ring, .46 4-C, .41 4-C 1/4" - 28
 Enya .15, SS.15, .19, .19X, .21CX, .25X 6.0 x 1mm
 Enya .35, .40, .40X, .40CX, .49X, .45, .45CX, GP.45CX, .50CX, .60FXIII, GP-60XF-4, GP.60XF-4H, .60XLF, GP.60XLF-4, .60 4-C, .80 4-C, .90 4-C, 120 4-C 7.0 x 1mm
 Enya R120 4-C, R120GP 4-C 8.0 x 1mm
 Fox .19RC, .19CL, .25RC, .25CL, .35CL, .40RC, .40CL, .50RCBB, .45RC Schnuerle, .40 Quickie 1/4" - 28
 Fox .60 - .74 Eagle 5/16" - 24
 Fitzpatrick .61 ABC 1/4" - 28
 HB .20 - .61 all models 1/4" - 28
 HP .21 - .61 all models 1/4" - 28
 HP VT.21 4-C, VT.49 4-C,
.40FRT Gold Cup, .61FRT Gold Cup
6.0 x 1mm
 HP 1.20 5/16" - 24
 Irvine .20 - .61 all models 1/4" - 28
 K&B .20 - .65 all models 1/4" - 28
 Magnum GP.25, GP.40, Pro.25, Pro.36SE, Pro.40SE, Pro.46SE 1/4" - 28
 Magnum GP65SE, Pro.61SE 5/16" - 24
 MDS .46 1/4" - 28
 MDS .25 - .40 6.0 x 1mm
 MDS .61 5/16" - 24
 Merco .33 - .40 1/4" - 28
 Merco .50, .61 5/16" - 24
 Moki .61 Long Stroke all models 1/4" - 28
 Moki .51RC 6.0 x 1mm
 Morris .45 - .60 8.0 x 1.25mm
 MVVS .15 - .61 6.0 x 1mm
 OS .20 - .50 all models, .61SFN-H Ring,
.61RFN-H ABC, FS-26 Surpass, FS-40 Surpass
1/4" - 28
 OS .60FP ABC, .61SF all version, .61RF ABC, .61RF-P, .61RX-H, .61SX-H, .61VR-M ABC, .65VR-M ABC, .65VR-DF ABC, .91VR-DF, .81VR-M, .91FSR, FF-240, FS-70 Surpass,
FS-91 Surpass, FS-120 Surpass II,
FS-120 Surpass SP, FS-61, FS-90, FS-120,
FT-120II, FT-160
5/16" - 24
 Picco .21 - .45 all models 1/4" - 28
 Quadra Q-35 5/16" - 24
 Rossi .21 6.0 x 1mm
 Rossi .40 - .90 8.0 x 1.25mm
 Royal .25RC BB ABC, 28RC BB ABC, .40RC ABC Schnuerle, .45RC BB Schnuerle ABC,
.46RC BB Schnuerle ABC
1/4" - 28
 Saito .40 - .60 4-C 6.0 x 1mm
 Saito .65 - .90 4-C 7.0 x 1mm
 Saito 1.20 - 2.70 4-C 8.0 x 1.25mm
 Supertigre .19 - .56 all models, .60G, 60ST 1/4" - 28
 Supertigre S-90K, S-61K, X61K ABC RE 5/16" - 24
 Thunder Tiger GP25, GP42, PRO25, PRO46, F-54S 1/4" - 28
 Thunder Tiger GP61, PRO61, PRO120, F-91S 5/16" - 24
 Webra .21 - .60 all models 1/4" - 28
 Webra .80 - .90 all models 8.0 x 1.25mm
 YS all 2-cycle models 8.0 x 1.25mm
 YS all 4-cycle models except .53 8.0 x 1.0mm
 YS .53 4-C 6.0 x 1.0mm

 

Use this Chart to find the range of props suitable for your engine type and size

Two - Stroke Engines  
 Prop Size Recomendation/Suggestion
Four - Stroke Engines
Prop Size Recomendation/Suggestion

.049

5.25x4, 5.5x4, 6x3.5, 6x4, 7x3 6x3  

.20-.21

9x5,10x5 9x6

.09

7x3,7x4.5,7x5 7x4

.40

10x6,10x7,11x4,11x5.11x7,11x7.5,
12x4,12x5,11x6

.15

8x5,8x6,9x4 8x4

.45-.48

10x6,10x7,10x8,11x7,11x7.5,12x4,
12x5,12x6,11x6

.19-.25

8x5,8x6,9x5 9x4

.60-.65 

11x7.5,11x7.75,11x8,12x8,13x5,
13x6,14x5,14x6,12x6

.20-.30

9x7,9.5x6,10x5 9x6

.80

12x8,13x8,14x4,14x6,13x6

.35-.36

9x7,10x5,11x4 10x6

.90
13x6,14x8,15x6,16x6,14x6

.40

9x8, 11x5 10x6

1.20

14x8,15x6,15x8,16x8,17x6,18x5,18x6,16x6

.45

10x6,11x5,11x6,12x4 10x7

1.60

15x6,15x8,16x8,18x6,18x8,20x6,18x6

.50

10x8,11x7,12x4,12x5 11x6

2.40

18x12,20x8,20x10,18x10

.60-.61

11x7.5, 11x7.75, 11x8,12x6 11x7

2.70

18x10,18x12,20x10,20x8

.70

11x8,12x8,13x6,14x4 12x6

3.00

18x12,20x10,20x10

.80

12x8,14x4,14x5 13x6

   

.90-.91

13x8,15x6,16x5 14x6

   

1.08

15x8,18x5 16x6

   

1.20

16x10,18x5,18x6 16x8

   

1.50

18x8,20x6 18x6

   

1.80

18x10,20x6,20x8,22x6 18x8

   

2.00

18x10,20x6,20x10,22x6 20x8

   

Warning: This chart is to be used as a general guide only!

You Must ALWAYS refer to your engine manufacturer's

instruction sheet as to the recommended size props

and rpm ranges for your specific engine!

ALWAYS WEAR EYE PROTECTION !!!

Below are some safety items that although seem elementary still need to be repeated regarding propellers and their use.

* Install the prop with the curved side of the blade facing forward and tighten the prop nut or bolt with the proper size wrench.

* Recheck the tightness of the nut or bolt often, especially on wood props which tend to compress and loosen more often.

* When starting the engine, keep spectators at least 20 feet clear of the model and out of the path of the propeller.

* Keep hands away from the prop as much as possible. Use a chicken stick or and electic starter.

* Keep face and body out of prop arc as engine is started and run.

* Make all adjustments from behind the prop except on pusher prop installations.

* Never throw anything into the prop to stop the engine. Use a kill switch or pinch off the engine's fuel supply.

* Discard any prop with nicks, scratches, splits, cracks or any other sign of damage. Never attempt to repair, alter or bend a prop.

* Don't run an engine in areas of loose gravel or sand for the prop can throw such material into your face and eyes. It's not a bad idea to wear eye protection.

* Keep loose clothing, shirt sleeves, and other such items away from the prop and avoid carrying objects that can fall into the prop such as pens, screwdrivers, etc.

* Be sure to keep the glow driver wire out of the prop path.

* If a spinner is used, be certain that it's edges are not in contact with the propeller blades.