Kelly boxes and adapters: square sizes and connection fit
A Kelly box is the square drive connection on a rotary drilling tool. An adapter transitions between different mating sizes. The box and adapter must be considered with the pin and engagement geometry; the square dimension is only one part of the connection.
Kelly Box & Adapter
How to specify the right configuration
Listed box sizes are 150 × 150, 200 × 200 and 250 × 250 mm. The listed adapter has a 250 × 250 mm female side and 200 × 200 mm male side. State the female and male sides explicitly to avoid reversing the requested transition.
Catalog specifications and listed options
Heavy-duty square Kelly boxes for rotary drilling tools in 150×150, 200×200 and 250×250 mm, plus a Kelly adapter with a 250×250 mm female connection and a 200×200 mm male connection. The standard tool connection is 200×200 mm; confirm pin-hole layout, engagement length and rig interface before ordering.
- 150×150 mm Kelly Box
- 200×200 mm Kelly Box
- 250×250 mm Kelly Box
- Kelly Adapter — 250×250 mm Female to 200×200 mm Male
Assembly review and inspection
Measure square profiles, engagement length, pin-hole diameters and hole-center positions on both sides. Compare with the unworn drawing where possible. Confirm the tool and Kelly bar interface before fabrication; worn corners or enlarged holes can make measurements from the old part misleading.
Which way does the listed Kelly adapter connect?
The listed adapter has a 250×250 mm female side and a 200×200 mm male side. Separate Kelly box options are 150×150, 200×200 and 250×250 mm; confirm engagement and pin-hole dimensions.
Preparing a quotation request in Saudi Arabia
- Identify the rig model, product, quantity and application; include the ground profile when specifying a cutting tool.
- Send a dimensioned drawing or clearly scaled photos. Identify mating components and distinguish measured dimensions from estimates.
- State the delivery city, required date and project documentation requirements. Confirm the included components before ordering.