When it comes to selecting clamps designed for underwater cameras, cinema monitors, or other equipment, the main question that we always get here at Ultralight Camera Solutions is: coarse or fine threads? For the longest time, Ultralight exclusively produced coarse-threaded clamps, a tradition that endures today, except for our AC-CSF28 clamps. The AC-CSF28 clamps were suggested by our largest dealer several years ago and have since become our best-selling clamp.
In an initial comparison between coarse and fine-threaded clamps, the primary difference lies in their knobs and the screws used for the bottom clamp half. Coarse-threaded clamps utilize a ¼”-20 Phillips pan machine screw, while finer-threaded ones use a ¼”-28 Phillips flat machine screw. The top clamp half with the through hole remains identical.
Coarse threads:
• Feature a larger pitch, resulting in fewer threads per inch, similar to the ¼”-20 machine screw.
• Are less susceptible to galling but require more threading area.
• Have fewer chances of cross-threading.
• Can endure more thread abuse before malfunctioning.
• Begin threading more easily into objects.
Fine threads:
• Have a smaller pitch, yielding more threads per inch, like the ¼”-28 machine screw.
• Are more prone to galling.
• Demand a longer threading area.
• Can sustain thread damage more easily.
• Allow for more precise adjustments.
• Are stronger than a similar bolt with coarse threads.
There are further considerations for larger bolts or machine screws, but they mostly concern manufacturers other than Ultralight.
The ultimate question remains: which is better, the fine-threaded AC-CSF28 clamp or the coarse-threaded AC-CSF clamp? Much of this decision comes down to personal preferences. While the AC-CSF28 clamp with finer threads provides greater precision when tightening the knob, does it make a significant difference? If everything is new and in perfect condition, it probably does. However, if the clamps haven't been cleaned and serviced regularly, will they still perform the same? Perhaps, or perhaps not. Personally, I admit that I don't maintain my equipment as diligently as I should, but I know others who are meticulous about it.
For me, the choice between the two clamps isn't so much about which one is better but rather which one suits my needs best. Here's how I believe the decision between coarse and fine-threaded clamps should be approached:
Coarse-threaded versus fine-threaded:
• Consider your equipment maintenance habits.
• Evaluate whether a finer adjustment justifies the higher cost of a fine-threaded clamp.
• Explore options for customizing the knob color. Both the AC-CSF and AC-CSF28 clamps are available in black, green, blue, and red, but the coarse-threaded AC-CSF also offers knobs in purple, pink, and yellow. • Assess the importance of uniformity if you require other clamp styles, such as longer ones or those with cutouts. The AC-CSF28 is the only clamp we manufacture with a fine-threaded bolt; all our other clamps feature coarse threads.
• Confirm the availability of repair and service parts; Ultralight offers them for all clamps.
If you still have questions after considering the above points, please don't hesitate to Contact Us at Ultralight. We are always eager to assist you!
