Countersunk vs. Pan Head
Comparing 2 standards across 12 specifications. 12 key differences identified.
Flat Head (Countersunk / CSK, standardized under ISO 7046 and DIN 965) screws feature a flat top face and a conical tapered underside (90° in ISO Metric, 82° in US Imperial, 100° in Aerospace). Designed to seat inside a matching chamfered hole, the head sits 100% flush with or slightly below the surface of the joined material.
Pan Head screws (standardized under ISO 7045 and DIN 7985) feature a low-profile rounded top, vertical cylindrical outer sidewalls, and a flat horizontal bottom bearing surface. Providing clean aesthetics and strong clamping force without cutting into workpiece materials, it is the most common machine screw head in electronics and appliance assembly.
Specification Comparison Table
12 Parameters| Parameter / Spec | ||
|---|---|---|
|
Standard Specifications
|
ISO 7046 / DIN 965 / ASME B18.6.3 | ISO 7045 / DIN 7985 / ASME B18.6.3 |
|
Primary Applications
|
Woodworking, door hinges, machine slides, aircraft aerodynamic skin | Consumer electronics, sheet metal electrical enclosures, general machinery |
|
Head Top Profile
|
100% Flat top face | — |
|
Countersink Angle (ISO Metric / DIN)
|
90 degrees | — |
|
Countersink Angle (US Imperial / ASME)
|
82 degrees | — |
|
Countersink Angle (Aerospace / NAS)
|
100 degrees (for thin structural aircraft skins) | — |
|
Length Measurement Rule
|
Overall Length (Measured from top of head to screw tip) | — |
|
Head Top Geometry
|
— | Slightly domed / curved low-profile top surface |
|
Outer Edge Geometry
|
— | Vertical cylindrical sidewalls with smooth radiused top transition |
|
Bearing Surface Profile
|
— | 100% Flat horizontal bearing surface |
|
Recess Recesses Supported
|
— | Phillips (PH), Pozidriv (PZ), Torx (TX), Slotted |
|
Countersinking Required
|
— | No (Mounts completely proud of the workpiece surface) |