First thing you need to figure out is what you actually have for fittings. Get a set of metric and standard thread pitch gauges, and a caliper.
@bigfunwmu
Here are the measurements that you suggested that I take. Thank you for your interest and any insight you can provide.
Using three thread pitch gauges...
A. Metric
B. Fractional
C. "SAE"
I found the
1.5 mm per thread pattern on the metric thread pitch gauge appeared to match the best.
Albeit, while the thread crown/crest points matched (aided by a flashlight back lighting the gauge and the threads), and the gauge nested fully into the valley/root of the threads, the thread angle appears more U shaped rather than V shaped, which allowed the 1.5 mm gauge to shift axially a little bit back and forth between thread flanks more than I am used to seeing.
Several attempts were made to find a better fit from the entire fan of choices in all three thread gauges, with 16 TPI being a distant second best on the fractional/SAE gauges, yet the crest cadence was off, evidenced after about 5 threads.
Thus, the closest actual match where the crests aligned for the entire length of threads was the 1.5 mm per thread gauge.
The threads appear to be straight... in other words, I could not detect any type of pipe like taper to the root diameter that grew in size as the threads advanced toward the body of the fitting. I clumsily attempted to verify this observation with the dial caliper, as described below.
Using a 6" dial caliper (wish I had better/smaller), reset to zero, measuring in thousandths, and converted to millimeters...
1. The
overall diameter, crest to crest was 0.551" / 14 mm
2. The
root diameter, root to root, was 0.500" / 12.7 mm at the entrance thread, and again was 0.500" / 12.7 mm at the terminating thread.
Based on your earlier response above, I will no longer call these fittings O-ring face seal, but they do have an O-ring, which appears to seat and seal in the flat face of the fitting, within the machined perimeter ring ledge that helps keep the O-ring in place.
Both the pump fitting and the cylinder fitting have raised machined ledges that appear to assist in locating the face mounted sealing O-ring. However, while the raised machined ledge on the pump fitting is around the perimeter, capturing the O-ring by surrounding the outside diameter of the O-ring, by distinct contrast, the raised machine ledge on the cylinder fittings is within the inside diameter of the O-ring, with no raised ledge on the outside diameter such as what the pump has. Likewise, in continued contrast, the pump fitting has no raised ledge capturing the inside diameter of the O-ring.
I have observed photos of ORSF fittings that have two machined raised ledges to keep the O-ring in place that capture both the inside AND the outside diameters of the O-ring, rather than just one OR the other, like the fittings I have.
I measured the metal dimensions that the O ring seats within and seals on the pump fitting.
3. Inner diameter of the
fluid orifice within the fitting, surrounded by the O-ring:
0.197" / 5 mm
4. Maximum
diameter of the O-ring seat, excluding the machined perimeter ring ledge that contains the O-ring:
0.370" / 9.4 mm
5.
Face width of the outer perimeter raised machined ring ledge that contains the O-ring:
0.065" / 1.65 mm (approximated, as the outer walls of this ledge taper into the first thread)
The foregoing measurements apply to the single outlet fitting on the 2 stage manual pump.
The following measurements apply to the single acting hydraulic cylinder fittings (there are two fittings, comprised of welded on male *******, where one ****** appears to be for a force gauge, and the other ****** is to receive the pressurized oil from the pump).
The metal dimensions that the O-ring seats within and seals on the cylinder fittings are as follows:
6. The
overall diameter, crest to crest was 0.550" / 14 mm
7. The
root diameter, root to root, was 0.500" / 12.7 mm at the entrance thread, and again was 0.500" at the terminating thread.
8. Inner
diameter of the fluid orifice within the fitting, that is also the inner diameter of the machined raised ledge that retains and centers the O-ring:
0.197" / 5 mm
9.
Maximum diameter of the O-ring seat, including the machined interior ring ledge within the inside diameter of the
O-ring: 0.455" / 11.56 mm (This is approximated, as the outside edges taper off into the first thread)
10.
Face width of the inner raised machined ledge defining the fluid orifice, surrounded by the O-ring that this ledge helps locate:
0.055" / 1.4 mm
Summary:
The
pump male fitting and the
cylinder male fitting have the
same 1.5 mm thread pitch.
Both also have seats for O-rings on their fitting faces.
However, the location of the raised machined ledges that retain the O-ring in position differ between the pump fitting and the cylinder fittings. The pump fitting has a machined raised ledge on the perimeter of the face, outside of the O-ring, with no ledge or protrusion at the orifice. On the other hand, the cylinder fitting has a machined raised ledge that defines the orifice, on the inside of the O-ring, without any perimeter raised ledge on the outside of the O-ring.
Another difference is that the male ****** fittings on the cylinder have fewer threads, 5 on one fitting and 6 on the other, while the pump male fitting has 10 threads. The cylinder fittings with fewer threads appear to have yet another O-ring land at the base of the threads, where an O-ring is rolled over the threads and seats like a hula hoop surrounding the threadless root diameter of the ******. The fewer threads on the cylinder fittings appear to be intentional, so as to accommodate this additional O-ring at the neck of the ******, just below the threads.
Finally, the
metric hex wrench size to open the threaded caps is 17 mm. The interiors of the caps between the pump and the cylinder appear to differ from each other in terms of number of threads, but they both have the same 1.5 mm thread pitch.
