Acme inlet threads have become the preferred thread configuration in the golf course irrigation market. An Acme thread has a flat apex and valley, and a wider tooth shape than an NPT thread. The wider tooth means it can withstand a greater load than a similarly sized square thread or NPT thread. An Acme thread also contains an O'ring to create a better seal. Hunter manufactures Acme Adapter Bushings in sizes ranging from 1 to 1 1/2 and multiple configurations are available to convert female and male NPT threads to ACME. Note: Acme threads are not compatible with NPT or BSP fittings.