---
code: "ASTM E4"
title: "Practices for force verification of testing machines"
institution: "ASTM"
category: "material-testing"
revision: "2021"
scope: "Describes practices to verify the force-indicating systems of static and quasi-static testing machines so that applied forces remain within ±1.0 % relative error over the stated verified range, primarily using ascending-load procedures."
testMethod: "Forces are applied in a series of steps with traceable standards; relative error is computed at each verification force. Unless otherwise specified, verification emphasizes increasing load; the lowest force meeting the ±1.0 % limit defines the start of the verified range."
specimenRequirements: "Verification uses reference force standards, not test specimens. Machine geometry, adapter stiffness, and environmental stability shall be controlled; warm-up and zeroing procedures follow E4 annex guidance."
url: "https://vectorbtc.com.tr/resources/standards/astm-e4/"
---

ASTM E4 is the North American counterpart to [ISO 7500-1](/resources/standards/iso-7500-1/). Instead of Class 0.5 / 1 / 2 tiers, E4 sets a single **±1.0 % relative error** limit across the verified interval. The **first force step** that still meets the limit becomes the machine’s documented range start—critical for marketing 50 kN and 300 kN capacity because low-load performance depends on load-cell quality and amplifier gain.

E4 verification typically runs ascending load unless a contract explicitly requires descending checks. ISO 7500-1 often examines reversibility and hysteresis in more detail.

| Topic | ISO 7500-1 | ASTM E4 |
| --- | --- | --- |
| Primary markets | Europe, Asia, international EN ISO | North America and ASTM-centric specs |
| Classification | Class 0.5, 1, 2 (relative error bands) | No classes; ±1.0 % target |
| Error treatment | Relative error, repeatability, reversibility | Total relative error in verified range |
| Load direction | Increasing and decreasing commonly assessed | Ascending load by default |

Vector documents force verification for hydraulic and electromechanical frames so customers can align calibration certificates with either ISO or ASTM quality systems before running metals programmes such as [ASTM E8/E8M](/resources/standards/astm-e8/) or [ISO 6892-1](/resources/standards/iso-6892-1/).