Additional technical information on electrical engineering here.


Fastening technology

White papers
Lightweight | white paper
The notion of "appearance" in coatings | white paper
  Selecting a fastener finish | white paper
  Heat treatment of fasteners | white paper
  Friction process capability | white paper
  Fastener solution for composites | white paper
  Hydrogen embrittlement | white paper
  Should fasteners be reused? | white paper
  Loosening joint | white paper
  Making the right choice | white paper

General tolerances, tables, standards

SI units system
Conversion tables
Conversion table for units of force
Conversion table for units of mechanical stress
Conversion table for units of work, energy and heat
Conversion table for units of power and heat flow
Conversion table for units of pressure for gases, vapours and liquids
Conversion of the units into SI units
Conversion tables metric – USA, USA – metric
Hardness comparison table
Designations of different national standards (according to ISO)
Basic tolerances and tolerance fields

Materials screws & nuts

Definition of mechanical properties for screws
Tensile strength Rm [N/mm2]
Yield strength ReL [N/mm2]
0.2% limit Rp0,2 [N/mm2]
Elongation at fracture A [%]
Tensile strength under wedge loading
Head soundness
Notch Impact Strength [Joule] ISO 83
Surface Flaws
Screws property class 4.6 to 12.9
Mechanical and physical properties of screws
Minimum ultimate tensile loads
Proof loads of screws
Materials, heat treatment, chemical compositions
Characteristics at elevated temperatures
Characteristics at higher strength (if ≥ 1 000 N/mm2)
Nuts property classes 04 to 12
Mechanical properties of nuts with ISO metricthreads (coarse)
Designation system and stress under proof loadfor nuts with height ≥ 0,5 d, but < 0,8 d
Test loads for nuts
Test loads for nuts 0,8 d
Chemical composition of nuts
Set screws property classes 14 H to 45 H
Mechanical properties
Materials, heat treatment and chemical composition
Screws, bolts, nuts
Marking and mechanical properties of hex headfasteners UNC / UNF
Marking and designation of fasteners with reduced loadability
Marking of fasteners
Marking of studbolts
Marking of nuts according to ISO
Marking of nuts according to DIN
Pairing screws and nuts ≥ 0,8 d
Marking of stainless steels screws and nuts
  DIN 7500 | white paper
Screws and nuts for high and low temperatures
Mechanical properties min. 0,2 % yield strength values at increased temperatures
Typical values for the density and static modulus of elasticity
Typical values for the coefficient of thermal expansion, thermal conductivity and heat capacity
Table of materials for temperature over +300 °C
Table of materials for low temperatures from–200 °C to –10 °C
Pairing materials for screws and nuts
Ductility of steels at low temperatures
Yield strength and tensile strength of steels at low temperatures
Elastic elongation of bolts with reduced shanks
Stainless steel fasteners
ISO-designated steel groups
Chemical composition of austenitic stainless steels
Chemical composition of corrosion resistant stainless steels
Distinctive properties of stainless steels
Time-temperature diagram of intergranular corrosion in austenitic stainless steels
Chemical stability
Technical arguments for the use of fasteners made from rust-resistant austenitic chrome-nickel steels A1, A2, A4
Mechanical properties for fasteners made from austenitic stainless steel
Minimum breaking torque MB min for screws madefrom austenitic steel with threads M1,6 to M16 (normal thread)
Reference values for 0,2 % Rp0,2 at higher temperatures as % of the values at room temperature
Marking of screws and nuts
  Galling of stainless steel fasteners | white paper
Fasteners of various materials
Non-ferrous metal
Special materials

Corrosion protection

  About corrosion | white paper
Galvanic process
Coating thicknesses for parts with external thread
Further galvanic coating processes
Further surface treatments

Arrangement, design, assembly

Selection of fasteners
Estimation of screw diameters
Fatigue resistance
Strength under dynamic load
Length of engaged thread
Recommended minimum lengths of engaged thread in cutted internal threads on components
Surface pressure when mounted
Typical values for allowable surface pressures for different materials
Surface pressure under the head of a hexagon screw
Surface pressure under the head of a socket head cap screw
Surface pressure under the screw head
Guide to the use of flat washers for screws and nuts
Friction and friction coefficients
Relation of friction coefficient classes to guideline values for various materials / surfaces and types of lubrication, for screw connections
Tightening method, tightening factor αA
Approximate values for static coefficient of friction μT in the separation joint
Guideline values for the tightening factor αA and the resulting pre-stress forces in assembly
Preload and tightening torques
How to use reference values
Approximate values for metric coarse threads VDI 2230
Approximate values for metric fine threads VDI 2230
Stud bolts with reduced shank
Tightening torques for plastic screws / Polyamide 6.6
Approximate values for austenitic stainless steel A1 / A2 / A4
Fasteners with internal drives and lower headshape
Flange screws and flange nuts
Reference values for tightening torque NORD-LOCK® washers wedge-locking system
High strength structural bolts
Securely fastened joints
Summary of constructive measures for locking screw joints
Overview of effectiveness for bolted joint locking solutions and solutions for prevention of loss
Shear loads for pins
Static shear loads for spring-pin joints
Construction recommendations
Construction recommendations
Direct assembly in thermoplastics using Delta PT® screws
Direct assembly in thermoplastics usingPT® screws / ecosyn®-plast
Sheet metal joints
Minimum breaking torque for sheet metal screws
Selection criteria for self-tapping Ensat® inserts
Internal drives for screws
Assembly tools
Shapes of driving features and assigned tool sizes

Metric ISO threads

Basic concept and nominal dimensions
Clearance fit on metric ISO threads
Tolerance fields for commercial screws and nuts
Limits for metric (standard) coarse threads
Selection series for coarse threads
Limits for metric fine threads
Selection series for fine threads
Permissible tolerances for plastic fasteners

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