socket head cap screw dimensions metric pdf
Metric socket head cap screws are high-strength fasteners with a hexagon socket for torque transmission. Designed for precision engineering‚ they feature a low-profile head and high tensile strength‚ ideal for applications requiring durability and reliability‚ with materials like high-grade alloy steel and compliance with international standards such as ISO 4762.
1.1 Definition and Applications
Metric socket head cap screws are cylindrical head fasteners with a recessed hexagon socket‚ designed for high-strength applications. Their compact design allows flush installation‚ making them ideal for machinery‚ automotive‚ and aerospace. These screws are commonly used where high torque‚ durability‚ and resistance to vibration are critical. They feature a unique combination of a cylindrical head and a hexagonal recess‚ enabling efficient torque transmission. Applications include precision machinery‚ dies‚ and jigs‚ where space constraints and high load requirements coexist.
1.2 Importance of Metric Dimensions
Metric dimensions are critical for socket head cap screws as they ensure standardization and consistency across global engineering applications. These dimensions‚ defined by ISO 4762 and DIN 912‚ provide precise measurements for thread size‚ head diameter‚ and body length. This standardization ensures interchangeability‚ simplifies design and manufacturing processes‚ and guarantees compatibility with international systems. Metric dimensions also facilitate accurate torque calculations and material strength specifications‚ making them essential for maintaining reliability and performance in diverse industrial and mechanical applications worldwide.
General Dimensions of Metric Socket Head Cap Screws
Metric socket head cap screws are standardized by ISO 4762 and DIN 912‚ ensuring consistent thread size‚ pitch‚ head diameter‚ and body length measurements in millimeters.
2.1 Thread Size and Pitch
Metric socket head cap screws are available in thread sizes from M1.6 to M48‚ with pitches ranging from 0.35mm to 5.0mm. The thread size and pitch are standardized according to ISO 261 and ISO 965‚ ensuring compatibility across applications. Smaller sizes like M1.6 and M2 are typically used in precision engineering‚ while larger sizes like M12 and M16 are common in heavy-duty machinery. The thread class 4g6g ensures tight tolerances‚ providing a secure fit. Torque calculations and material strength are directly influenced by these dimensions. Proper selection ensures optimal performance and longevity.
2.2 Head Diameter and Socket Size
The head diameter of metric socket head cap screws ranges from 3.00mm for M3 to 63.00mm for larger sizes‚ ensuring compatibility with various applications. The hexagon socket size (s) varies from 1.5mm for M2 to 10mm for M42‚ providing a secure drive system. Head height (k) is typically 2.5 to 4 times the pitch‚ ensuring proper engagement. These dimensions are standardized by ISO 4762 and DIN 912‚ guaranteeing consistency. The socket size directly influences torque capacity‚ making it crucial for application suitability and performance.
2.3 Body Diameter and Length
The body diameter of metric socket head cap screws matches the nominal thread size‚ ranging from 1.6mm to 48mm. Screw lengths vary‚ with nominal lengths (L) starting at 4mm for smaller sizes and increasing progressively. Thread length (T) is equal to the screw length for shorter screws‚ while longer screws have partial threading. Body diameter and length must align with ISO 4762 and DIN 912 standards‚ ensuring proper fit and load-bearing capacity in precision engineering applications.
Mechanical Properties
Metric socket head cap screws offer high tensile strength‚ with Class 12.9 steel providing exceptional durability. They meet ISO 898-1 standards‚ ensuring reliability in demanding applications.
3.1 Material Grades and Strength Classes
Metric socket head cap screws are primarily made from high-grade alloy steel‚ classified as Class 12.9‚ offering exceptional tensile strength and resistance to stress. This class is the most common‚ providing a yield strength of approximately 1‚080 N/mm². Lower classes like 8.8 and 10.9 are also available but less frequently used. Stainless steel options are offered for corrosion resistance. All materials comply with ISO 898-1 standards‚ ensuring reliability in demanding engineering applications.
3.2 Tensile Strength and Yield Point
Metric socket head cap screws in Class 12.9 exhibit a minimum tensile strength of 1‚220 N/mm² and a yield point of 1‚080 N/mm². These values ensure high performance under stress. Torque calculations‚ per VDI 2230‚ aim to achieve approximately 800 MPa stress in threads. This ensures optimal tightening without risking material failure. The screws maintain stability across temperatures from -50°C to 300°C‚ making them suitable for diverse engineering applications requiring both strength and reliability. Their mechanical properties are critical for precision and durability in industrial use.
Torque Specifications
Torque specifications for metric socket head cap screws are calculated to achieve approximately 800 MPa stress in threads‚ ensuring proper tightening without exceeding material limits. This method‚ outlined in VDI 2230‚ provides precise guidelines for various screw sizes‚ materials‚ and lubrication conditions to optimize performance and prevent overload.
4.1 Torque Calculation Methods
Torque calculation methods for metric socket head cap screws are systematic and precise‚ typically following the VDI 2230 standard. This approach calculates torque to achieve a specific stress level in the screw threads‚ ensuring optimal clamping force without risking material failure. The method considers factors such as screw size‚ thread engagement‚ and material properties‚ providing a reliable framework for determining the correct torque for various applications and ensuring structural integrity.
4.2 Recommended Torque Values by Screw Size
Recommended torque values for metric socket head cap screws vary by size and material. For example‚ M3 screws typically range from 0.5 to 1.5 Nm‚ while M6 screws range from 5 to 8 Nm. Larger sizes‚ like M10‚ may require 15 to 25 Nm. These values are calculated to achieve approximately 800 MPa stress in the threads‚ ensuring optimal clamping force without exceeding material limits. Torque specifications are often detailed in product standards like ISO 4762 and DIN 912‚ ensuring consistency across applications.
4.3 Lubrication Effects on Torque
Lubrication significantly impacts torque values for metric socket head cap screws. Reduced friction from lubricants lowers the required torque‚ preventing over-tightening. Standards like ISO 4762 often assume dry conditions‚ so adjustments are needed when lubrication is applied. Proper lubrication ensures consistent torque application‚ avoiding preload variability and potential joint failure. It is critical to account for lubrication effects to maintain accuracy in torque calculations and ensure optimal joint integrity during assembly.
Head and Socket Dimensions
Head and socket dimensions for metric socket head cap screws include hexagon socket size‚ head diameter‚ and key engagement‚ varying by screw size and application needs.
5.1 Hexagon Socket Size (s)
The hexagon socket size (s) varies by screw diameter‚ ensuring compatibility with standard tools. For example‚ M3-M5 screws use a 1.5 mm socket (s=1.5)‚ while M6-M8 use 2 mm (s=2). Larger sizes like M10-M12 have a 3 mm socket (s=3)‚ and M14-M16 use 4 mm (s=4). This progression ensures optimal torque transmission and ease of installation across different applications‚ adhering to ISO 4762 standards for consistency and reliability.
5.2 Head Height (k)
The head height (k) of metric socket head cap screws increases proportionally with the screw size to ensure structural integrity. For example‚ M3 screws have a head height of 1.5 mm‚ while M6 screws have a head height of 4 mm. Larger screws‚ such as M12‚ feature a head height of 6 mm. This dimension is critical for maintaining the screw’s strength and ensuring proper engagement with the socket tool‚ adhering to ISO 4762 standards for precise engineering applications.
5.3 Key Engagement Dimensions
Key engagement dimensions ensure proper tool engagement with the socket head. The depth (t) and width (s) of the hexagon socket must align with ISO 4762 standards. For metric screws‚ the key engagement depth typically ranges from 0.2 mm for smaller sizes like M1.6 to 1.0 mm for larger sizes like M48. These precise dimensions prevent wear and ensure reliable torque transmission‚ maintaining structural integrity and tool compatibility across various applications.
Body and Grip Length Dimensions
Body and grip lengths are critical for proper fastening. Nominal screw length (L) includes grip (G) and thread (T) lengths‚ standardized per ISO 4762 for sizes M3 to M48.
6.1 Nominal Screw Length (L)
Nominal screw length (L) measures from the screw’s tip to the underside of the head. For metric socket head cap screws‚ L varies across sizes‚ ensuring compatibility with diverse applications. Screws with lengths equal to or shorter than specified are threaded to the head‚ while longer screws have partial threading. Compliance with ISO 4762 ensures standardization‚ making L a reliable measure for design and installation purposes across industries.
6.2 Grip Length (G)
Grip length (G) is the unthreaded portion of the screw shank‚ measured from the tip to the first thread. It ensures proper seating without thread engagement‚ preventing material damage. For metric socket head cap screws‚ G is critical in applications requiring precise assembly. Compliance with ISO 4762 guarantees standardized dimensions‚ ensuring compatibility and reliability across various engineering applications.
6.3 Thread Length (T)
Thread length (T) is the distance from the tip of the screw to the end of the threads. For metric socket head cap screws‚ screws with lengths equal to or shorter than specified dimensions are threaded to the head. This ensures proper engagement and prevents over-tightening. Compliance with ISO 4762 and DIN 912 standards guarantees precise thread specifications‚ making these screws suitable for a wide range of applications‚ from M3 to M48 sizes.
Material and Finishes
Metric socket head cap screws are made from high-grade alloy steel (Class 12.9) and stainless steel‚ offering superior strength and corrosion resistance. Finishes include self-color and black oxide.
7.1 Steel Grades (Class 12.9)
Class 12.9 steel grades offer exceptional tensile strength‚ up to 1200 MPa‚ making them ideal for high-stress applications. Heat-treated via quenching and tempering‚ these screws provide superior durability and resistance to wear. They are widely used in machinery‚ automotive‚ and construction due to their reliability in harsh environments. The steel’s high strength-to-weight ratio ensures minimal deformation under load‚ while its corrosion resistance‚ though moderate‚ can be enhanced with coatings like black oxide or zinc plating for added protection.
7.2 Stainless Steel Options
Stainless steel socket head cap screws offer excellent corrosion resistance‚ making them ideal for harsh environments. Commonly available in grades like 304 and 316‚ they provide superior durability in marine‚ medical‚ and food processing applications. The self-color or passivated finish enhances their resistance to rust and wear. These screws are preferred for their combination of strength‚ corrosion protection‚ and aesthetic appeal‚ ensuring long-term reliability in demanding conditions while maintaining a clean‚ polished appearance.
7.3 Corrosion Protection Methods
Corrosion protection for metric socket head cap screws is achieved through various methods. Stainless steel options inherently offer resistance‚ while coatings like zinc plating or organic treatments provide additional layers of defense. Passivation enhances stainless steel’s natural corrosion resistance. Electroplating with materials such as zinc or chrome is also common. These methods ensure durability in harsh environments‚ extending the lifespan of the screws by protecting them from rust and degradation‚ making them suitable for outdoor and high-moisture applications.
Standards and Specifications
Metric socket head cap screws comply with ISO 4762‚ DIN 912‚ and BS 4168 standards‚ ensuring interchangeability and adherence to strict dimensional and mechanical requirements.
8.1 ISO 4762 and DIN 912 Compliance
Metric socket head cap screws must comply with ISO 4762 and DIN 912 standards‚ which define dimensional‚ mechanical‚ and material requirements. These standards ensure interchangeability and reliability in engineering applications. DIN 912 specifies technical delivery conditions‚ while ISO 4762 focuses on dimensional and material standards. Compliance guarantees high strength‚ durability‚ and adherence to international norms‚ making these fasteners suitable for demanding environments and precise assembly needs across various industries.
8.2 Product Marking Requirements
Product marking for metric socket head cap screws must adhere to ISO 4762 and DIN 912 standards. Screws are typically marked with their property class (e.g.‚ 12.9)‚ manufacturer’s identifier‚ and size designation. These markings ensure traceability and verify compliance with specified strength and dimensional requirements. Additionally‚ stainless steel screws may include material designations. Proper marking is essential for quality assurance and to meet international standards‚ ensuring reliability in high-performance applications.
8;3 Class 12.9 Properties and Applications
Class 12.9 socket head cap screws are manufactured from high-grade alloy steel‚ heat-treated to achieve a Rockwell hardness of 38-44 HRC. They exhibit exceptional tensile strength‚ with a minimum yield strength of 1080 N/mm²‚ making them ideal for high-stress applications. These screws are commonly used in machinery‚ automotive‚ and construction industries where reliability and durability are critical. They comply with ISO 898-1 standards and offer excellent resistance to corrosion‚ with optional coatings available for enhanced protection.