Essential Variables For PQR Qualification Under MIL-STD-3040A

Plus: Audit Preparation and Checklist

What You Need To Know: Article 3 of 7

When developing a PQR (Procedure Qualification Record) and resulting WPS (Weld Procedure Specification) for components being fabricated to meet MIL-STD-3040A, it is very important to understand and document the essential variables involved in your welding procedure. These variables ensure repeatability, traceability and mechanical soundness of the weldments, but will also require requalification if changes are made to these variables outside of their acceptable range limits as specified in MIL-STD-3040A.

Military fabricators should also be prepared for periodic audits of their production facility, personnel and recorded documentation. Our team at United Technical Inc. can assist with the initial qualification of the welding process and also partner with defense contractors to provide guidance and oversight through ongoing production and audit preparation.

Here is what must be tracked during the Procedure Qualification Record (PQR) process as shown in Table V. from MIL-STD-3040A below:

Base Materials

• Type, thickness, backing materials and configuration / joint design

• Must conform to MIL or AWS standards

• If any change in base material type or thickness occurs, requalification may be required

Filler Materials

• Classification and manufacturer

• Diameter and lot number

• Flux (if applicable) must also be documented

Shielding Gas

• Type, composition and flow rate

• Some flow rate variations are allowed within specified limits

• For processes like GMAW or GTAW, any changes here are considered essential variables

Electrical Parameters

• Voltage, amperage, travel speed, and polarity 

• To allow for inevitable production variation, there are allowable limits for variation in voltage, amperage and travel speed without having to requalify

• Heat input (calculated based on these parameters) must be recorded and within acceptable ranges

Welding Process

• Process (e.g., SMAW, GMAW, GTAW, FCAW, etc.)

• Method of application

• Manual, semi-automatic, mechanized or robotic application

• A change in welding process requires requalification

Welding Position

• 1G, 2G, 3G, 4G, etc.

• A change in position is an essential variable and could trigger requalification

Preheat & Interpass Temperatures

• Minimum and maximum temperatures must be controlled and monitored

• Deviation from specified temps can affect mechanical properties

Pass Sequence & Technique

• Number of passes

• Weaving vs stringer beads

• Direction of welding (uphill vs downhill)

Post Weld Heat Treatment (PWHT)

• Required or not? If performed, document time, temp, and method

• Changes to PWHT parameters require requalification

Table V. MIL-STD-3040A (14 February 2024)

Audit Preparation and Checklist for MIL-STD-3040A

Defense contractors can be subject to periodic audits throughout their contract duration.  In order to pass a MIL-STD-3040A audit, a robust quality system, proper documentation and consistency are key.

Here is what you should have ready:

Document Control

• All WPS, PQRs, and WPQs must be current, controlled, and accessible

• Revisions must be clearly marked and dated

Personnel Qualification Records

• Welders and NDT inspectors must have up-to-date certifications

• Maintain evidence of SNT-TC-1A Level II qualifications for NDT personnel

Weld History Logs

• Track each production weld to its corresponding WPS

• Include lot numbers of filler materials and shielding gases used

Material Traceability

• Maintain traceability from base metal to final weld

• Mill certs and inspection reports must be organized by heat/lot numbers

Inspection & Testing Records

• Keep visual, radiographic, ultrasonic, and mechanical test reports on file

• Record any repairs or rework with root cause analysis and corrective actions

Visual Records

• Photographic evidence of joint preparation, welds, and post-weld condition is a major plus in an audit

United Technical Inc. - Tips from the experts:

• Standardize naming conventions across all documents

• Create a digital dashboard to flag expiring welder qualifications and WPS reviews

• United Technical can conduct mock audits every 6 months to keep you prepared

Final Word: The more proactive your documentation, the smoother your compliance journey. Track your essential welding variables with intention, and always be ready to demonstrate control, consistency, and quality during an audit.

Contact United Technical Inc For More Information

Robert Dines

CEO

United Technical Inc.

Phone: 248-667-9185