Does ISO 898-1 specify tightening preload or torque?

No. ISO 898-1:2013 specifies mechanical and physical fastener properties and explicitly excludes torque/clamp-force performance. This page only multiplies user-supplied stress area, reference stress and fraction.

Can the result be used as a joint preload target?

Not by itself. A joint target requires load, stiffness, separation, fatigue, embedment, temperature, thread and bearing limits, tightening scatter and verification of the assembly method.

Why was the torque output removed?

A generic nut-factor preset cannot represent the actual friction distributions, geometry, coating, lubrication and assembly process. Torque/clamp behaviour should be established from qualified procedure or testing such as ISO 16047.

Scoped Engineering Calculation

Bolt Axial Reference-Load Fraction

Calculate F = η·σref·As from three user-supplied values. This is a stress-area multiplication, not an automatic joint-preload or tightening-torque design.

User-Supplied DataNo Generic TorqueNot “Preload per ISO”

Αριθμητικό αποτέλεσμα

Selected axial load η·σref·As

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Reference-area load σref·As

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Selected axial stress η·σref

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Input fraction

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Arithmetic model

F_{αναφορά} = σ_{αναφορά}A_s; F = ηF_{αναφορά}

Because 1 MPa = 1 N/mm², stress times stress area gives newtons. The page does not decide whether σref should be proof stress, lower yield strength, 0.2% proof strength or a lower design value; use the exact value applicable to the fastener, diameter, temperature and governing procedure.

What ISO 898-1 actually covers

ISO 898-1:2013, confirmed in 2025 and currently marked for revision, specifies mechanical and physical properties of carbon/alloy-steel bolts, screws and studs at 10–35 °C. Its stated metric-thread scope is M1.6–M39, and it explicitly does δεν specify torque/clamp-force performance, fatigue resistance or shear resistance.

Joint design and assembly

VDI 2230 Part 1:2015 covers systematic joint calculation, including minimum clamp load, preload changes, assembly preload, tightening torque and strength verification. This three-input page does not claim VDI conformity. ISO 16047:2005+Amd1:2012 specifies torque/clamp-force test conditions; it is not replaced by a universal K preset.

Source responsibility: obtain As and σref from the current licensed product/thread standard, verified manufacturer data or material certificate. For stainless, elevated/low temperature, reduced-head geometry or sizes outside scope, use the applicable source rather than ISO 898-1 values.