Bronze 544-H04

Also known as Phosphor Bronze, this is a good choice for low-force gears such as watch gears. It is fairly fatigue-resistant and is commonly used for things like electronics leads and specialty springs.

Overall Sizes
Largest Outside Diameter (OD_max)	2.425 in
Max Length (L), no bored features	9.5 in	Limited by machine clearance.
Max Length (L), with bored features	6.25 in	Features cut into the face of the part require more room for the tool to move into the part, subtracting from available room in the machine.
Minimum Wall Thickness	0.02 in
Max L:D ratio with no Tailstock	4	If the part is too long compared to its diameter, the cutting forces will push the part away, causing inaccurate dimensions. Allowing for a Tailstock can help exceed this limit.
Max L:D ratio with Tailstock	10	Even with a Tailstock supporting the end of the part, cutting forces near the middle of a long part can cause deflection and inaccurate dimensions.

Feature Sizes
Maximum Radial Step	0.826 in	0.119 in minimum groove width
Maximum Radial Step	0.629 in	0.060 in minimum groove width
Maximum Boring Depth	1.790 in	For hole diameters 0.258 in and larger
	1.340 in	For hole diameters 0.196 in and larger
	0.890 in	For hole diameters 0.133 in and larger
Minimum Groove Width	0.119 in	0.826 in maximum depth
Minimum Groove Width	0.060 in	0.629 in maximum depth
Internal Threads
External Threads

Gears
Minimum Number of Teeth	12	Our gears are made by hobbing or single-tooth cutting, both of which have limitations under a tooth count of 12.
Maximum Helix Angle, Helical Gears	45°	Limited by machine clearance.
Available Tooth Sizes	16 DP hob	20° pressure angle
	24 DP hob	20° pressure angle
	1.5 mod hob	20° pressure angle
	1.25 mod hob	20° pressure angle
	1 mod hob	20° pressure angle
	0.8 mod hob	20° pressure angle
	0.7 mod hob	20° pressure angle
	0.6 mod hob	20° pressure angle
	0.5 mod hob	20° pressure angle
Maximum Gouge	3 times module	The maximum allowable distance for the gear cutting tool to enter the part. Features nearby to the gear surface will get gouged if they are too close.
Maximum Number of Gears per Part	4	Be aware of gouging when combining gears in one part. See: How to Make Stacked Compound Gears and Herringbone Gears

Tolerances
Diameter Tolerance	±0.005 in
Length Tolerance	±0.005 in
Thread Tolerance
Gear Class

Material Properties
Not tested or guaranteed. Use appropriate safety factors in design.
UNS name	C54400
Density	8.89 g/cc
Yield Strength	395 MPa
Ultimate Strength	470 MPa
Elastic Modulus	103 GPa
Hardness	40HRB