ASME/ANSI B18.6.3 Cross Recessed Pan Head Machine Screws
ASME/ANSI B18.6.3 Cross Recessed Pan Head Machine Screws are designed for fastening components to pre-tapped holes, threaded inserts, or nuts where a raised screw head is acceptable. Unlike countersunk screws, the pan head remains above the mounting surface and does not require a countersunk hole, which can simplify the preparation of the mating component. The rounded head provides a defined bearing surface for securing the attached part while maintaining a relatively compact profile.
The cross-recessed drive provides straightforward access for installation with a compatible screwdriver or bit, making these screws practical for assembly and service work. They are commonly selected for equipment panels, electrical and instrument enclosures, brackets, machine components, sheet-metal assemblies, and general mechanical equipment. Depending on the application, customers can select the appropriate thread size, screw length, material, mechanical grade, and surface finish to match the mating thread and required service conditions.


Specification:
The specification of ASME/ANSI B18.6.3 Cross Recessed Pan Head Machine Screws include the following details:
| Item | Specification |
|---|---|
| Product Standard | ASME/ANSI B18.6.3 |
| Product Type | Cross Recessed Pan Head Machine Screw |
| Head Style | Pan Head |
| Drive Type | Cross Recessed |
| Thread System | Inch |
| Thread Series | UNC/UNF |
| Size Range | #2-1/2" |
| Material | Caron Steel, Alloy Steel,Stainless Steel |
| Carbon Steel Standard | SAE J429 |
| Stainless Steel Standard | ASTMF593 |
| Surface Treatment | Passivation, Zinc Plated, Black Oxidation,Bright Finish |
Dimension Chart of ASME/ANSI B18.6.3 Cross Recessed Pan Head Machine Screws:
The dimension chart provides the key measurements for selecting the screw and matching it with the mating thread and installation tool. Nominal diameter and length determine the basic thread engagement, while head diameter and head height should be checked when space around the screw head is limited. The cross-recess size is also important for selecting the correct screwdriver or driver bit.

| Mon | #2 | #3 | #4 | #5 | #6 | #8 | #10 | #12 | 1/4 | 5/16 | 3/8 | 7/16 | 1/2 |
| P | 56|64 | 48|56 | 40|48 | 40 | 32|40 | 32|36 | 24|32 | 24|28 | 20|28 | 18|24 | 16|24 | 14|20 | 13|20 |
| dk max | 0.167 | 0.193 | 0.219 | 0.245 | 0.27 | 0.322 | 0.373 | 0.425 | 0.492 | 0.615 | 0.74 | 0.863 | 0.987 |
| dk min | 0.155 | 0.18 | 0.205 | 0.231 | 0.256 | 0.306 | 0.357 | 0.407 | 0.473 | 0.594 | 0.716 | 0.837 | 0.958 |
| k max | 0.062 | 0.071 | 0.08 | 0.089 | 0.097 | 0.115 | 0.133 | 0.151 | 0.175 | 0.218 | 0.261 | 0.305 | 0.348 |
| k min | 0.053 | 0.062 | 0.07 | 0.079 | 0.087 | 0.105 | 0.122 | 0.139 | 0.162 | 0.203 | 0.244 | 0.284 | 0.325 |
| M | 0.097 | 0.105 | 0.115 | 0.152 | 0.159 | 0.175 | 0.192 | 0.252 | 0.274 | 0.343 | 0.382 | 0.406 | 0.428 |
| No. | 1 | 1 | 1 | 2 | 2 | 2 | 2 | 3 | 3 | 4 | 4 | 4 | 4 |
| t max | 0.052 | 0.061 | 0.071 | 0.072 | 0.08 | 0.097 | 0.113 | 0.124 | 0.144 | 0.173 | 0.213 | 0.239 | 0.26 |
| t min | 0.034 | 0.043 | 0.053 | 0.046 | 0.055 | 0.071 | 0.089 | 0.098 | 0.118 | 0.149 | 0.19 | 0.214 | 0.235 |
- RELATED SCREW LISTS:
- ANSI/ASME B18.3 Stainless Steel American Standard Countersunk Head Torx Screw
- ANSI/ASME B18.3 Stainless Steel Hexagon Socket Button Head Cap Screws
- ANSI/ASME B18.3F Stainless Steel Hex Socket Countersunk Head Machine Screw
- American Standard ASME/ANSI B18.3 Hexagon Socket Head Cap Screws
- DIN7991 Stainless Steel Hex Socket Countersunk Head Cap Screws
- ISO7380 Stainless Steel Hexagon Socket Button Head Screws
- DIN963 90° Stainless Steel Slotted Countersunk Head Screws
- DIN965 Stainless Steel Cross Recessed Countersunk Head Screws
- DIN84 Stainless Steel Slotted Cheese Head Screws
- DIN7971 Stainless Steel Slotted Pan Head Tapping Screws
Application of ASME/ANSI B18.6.3 Cross Recessed Pan Head Machine Screws:
Panels and Enclosures
The raised pan head provides an accessible fastening point on equipment panels and enclosures, while its bearing surface helps secure thin components without requiring a countersunk recess. These screws are suitable for control cabinets, electrical enclosures, instrument panels, and equipment covers assembled with tapped holes or threaded inserts.
Components Requiring Regular Access
The cross-recessed head is convenient where screws may need to be installed, removed, or adjusted during assembly and maintenance. They are suitable for access covers, inspection plates, sensor housings, protective guards, and serviceable machine components, where the driver needs straightforward access to the screw head.
Thin Parts and Threaded Inserts
The machine-screw thread makes this design particularly useful for sheet-metal parts and thin fabricated components fitted with threaded inserts or captive nuts. The pan head distributes the clamping load over a defined bearing area without requiring the additional machining needed for a countersunk head.
Production Assembly
For repeated installation, the standard cross-drive configuration and consistent pan-head geometry make these screws practical for production assembly using manual or powered screwdrivers. They can be specified in different thread sizes, materials, grades, and finishes to suit the assembly environment.
