S&G 6730 vs S&G 6741 Tolerances
Posted: Sat Jun 27, 2020 4:02 pm
After looking through Sargent and Greenleaf's current catalog and the previous addition of their catalogue I noticed that the tolerances for the S&G 6741 and S&G 6730 were both +/- 1.25 in the current edition and +/-0.5 for the 6730 and +/-1.0 for the 6741 in the previous. I thought that maybe there was a change in machining and the two locks were made off of the same machinery thus the same tolerances. Regardless of what happened between the two catalogs I wanted to examine the two locks a little closer
The 6741 on the left is a 2015 production run and the 6730 on the right is a 2019 production run.
The 6741 Drive Cam had a diameter of 29.45mm, Contact Area of 8.96mm, and Contact Area depth of 4.24mm.
The 6730 Drive Cam had a diameter of 29.49mm, Contact Area of 10.94mm, and Contact Area Depth of 4.74mm.
The 6741 Lever had a fence height of 2.47mm, Fence width of 2.78mm, Nose hight of 13.65mm, and a Lever length of 50.48mm.
The 6730 Lever had a fence height of 2.33mm, Fence width of 3.83mm, Nose height of 13.44mm, and a Lever length of 45.22mm.
We can also see the quality differences in the levers besides material. The fence on the 6741 is also rounded where as the 6730's fence is rhombic.
The 6741 Wheel thickness is ~3.60mm, Wheel diameter is ~44.55mm, and Gate opening is 6.17mm.
The 6730 Wheel thickness is ~3.80mm, Wheel diameter is ~44.90mm, and Gate opening is 6.17mm.
The thickness difference is probably a cost reduction measure for the 6741, but note that the gate openings are the same on both wheel packs.
The 6741 Fly width was ~3.78mm.
The 6730 Fly width was ~3.82mm.
There is less material on the 6741 fly's than on the 6730. This again is most likely a cost reduction measure.
The 6741 Driver width was ~3.50mm.
The 6730 Driver width was ~3.52mm.
After going through this exercise we can see that the tolerances are tighter on the 6730 given the Fence, Driver, Fly, and Gate measurements verses the 6741. Statistically I should have at least 3 of each lock and preferably a larger sample size from the same production run, but given my lock budget this was the best that I can do at the moment. Having the two locks side by side like this did highlight some of the machining differences that I would have other wise not noticed, and that alone I found interesting. With the measurements done it was even more enlightening to see how the diffrances related to lock tolerances and manipulation. The nose on the 6741 does sit a little lower in the contact area than the nose on the 6730. I am able to manipulate the 6741 quicker than the 6730 that I have. However my manipulation times of the 6741 are still slower than the CDL-3 I have and the Chinese junk in the Sparrows Vault.
I hope this is of some interest to some out there.
The 6741 on the left is a 2015 production run and the 6730 on the right is a 2019 production run.
The 6741 Drive Cam had a diameter of 29.45mm, Contact Area of 8.96mm, and Contact Area depth of 4.24mm.
The 6730 Drive Cam had a diameter of 29.49mm, Contact Area of 10.94mm, and Contact Area Depth of 4.74mm.
The 6741 Lever had a fence height of 2.47mm, Fence width of 2.78mm, Nose hight of 13.65mm, and a Lever length of 50.48mm.
The 6730 Lever had a fence height of 2.33mm, Fence width of 3.83mm, Nose height of 13.44mm, and a Lever length of 45.22mm.
We can also see the quality differences in the levers besides material. The fence on the 6741 is also rounded where as the 6730's fence is rhombic.
The 6741 Wheel thickness is ~3.60mm, Wheel diameter is ~44.55mm, and Gate opening is 6.17mm.
The 6730 Wheel thickness is ~3.80mm, Wheel diameter is ~44.90mm, and Gate opening is 6.17mm.
The thickness difference is probably a cost reduction measure for the 6741, but note that the gate openings are the same on both wheel packs.
The 6741 Fly width was ~3.78mm.
The 6730 Fly width was ~3.82mm.
There is less material on the 6741 fly's than on the 6730. This again is most likely a cost reduction measure.
The 6741 Driver width was ~3.50mm.
The 6730 Driver width was ~3.52mm.
After going through this exercise we can see that the tolerances are tighter on the 6730 given the Fence, Driver, Fly, and Gate measurements verses the 6741. Statistically I should have at least 3 of each lock and preferably a larger sample size from the same production run, but given my lock budget this was the best that I can do at the moment. Having the two locks side by side like this did highlight some of the machining differences that I would have other wise not noticed, and that alone I found interesting. With the measurements done it was even more enlightening to see how the diffrances related to lock tolerances and manipulation. The nose on the 6741 does sit a little lower in the contact area than the nose on the 6730. I am able to manipulate the 6741 quicker than the 6730 that I have. However my manipulation times of the 6741 are still slower than the CDL-3 I have and the Chinese junk in the Sparrows Vault.
I hope this is of some interest to some out there.