Answer: While the terms are often used interchangeably, there is a technical difference. A traditional turnbuckle typically features an open body design, where the threads are exposed. A bottlescrew or rigging screw, by contrast, has a closed, tubular body that encases and protects the threads. For power line construction, our open-body turnbuckles are often preferred because they provide a clear view of the thread engagement, which is a key safety inspection point. The enclosed design of bottlescrews is common in applications where aesthetics or maximum thread protection are a priority. Both devices operate on the same principle of opposing threads to adjust tension.