Adjustable screws are used to adjust the balance from string to string. At times you may need to adjust the output on a particular string because it may lack the output for your picking or playing style. You may need to lower a pole to decrease the output on a particular string when the output is too loud. Depending on how much adjustment you have for a particular string, the adjustment is usually minimal with not much affect.

The original humbuckers designed by Seth E. Lover was first drawn without a row of adjustable pole pieces. Gibson felt the new and improved humbucking design should have adjustable poles as a selling point because the single coil P-90s had them. Many other pickup manufactures have designed pickups that incorporated adjustable screws for each string. DeArmond’s single coil “Dynosonic” pickup used on many Gretsch & Guild guitars used adjustable screws that would lift or lower a 1/4″ inch Alnico rod magnet for desired string balance.

The Gretsch Filtertron pickups designed by Ray Butts used 12- 6/40 fillister head, slotted, steel machine screws and the Hi-Lo Tron single coil pickups used a headless, slotted set screw.