Skip to main content
True Precision Machining
Engineering hub

Engineering · Standards & Glossary

Standards, specs & glossary.

The acronyms, spec families, and standards bodies you'll see on aerospace, medical, and defense drawings — what each one means and when it applies.

01 · Quality systems

The QMS standards behind every aerospace order.

Customers don’t just buy parts — they buy parts under a quality management system. AS9100 (aerospace), ISO 13485 (medical devices), and ISO 9001 (general) are the dominant frameworks. We hold both ISO 9001 and AS9100 — flow-down requirements ride on every PO.

ISO 9001

Quality Management Systems

International baseline QMS standard. Process documentation, corrective action, internal audits. AS9100 is built on top of this.

AS9100

Aerospace Quality Management Systems

ISO 9001 + aerospace-specific requirements (configuration management, FOD prevention, risk management, product safety). Required by virtually all aerospace primes.

AS9102

First Article Inspection (FAI)

Aerospace standard for documenting first-article inspection — Forms 1 (part identification), 2 (raw material/process), 3 (characteristic accountability).

ISO 13485

Medical Device QMS

Medical-device equivalent of AS9100. Adds traceability, sterilization control, and biocompatibility requirements. Required for surgical-instrument and implant work.

Nadcap

Aerospace Special Process Accreditation

Industry-managed accreditation for special processes — heat treat, NDT, chemical processing, welding. Required when the prime mandates Nadcap-approved subcontractors.

ITAR Registered

International Traffic in Arms Reg.

Registered with U.S. Department of State DDTC for handling defense articles. Not a quality standard per se but commonly bundled with QMS audits.

02 · Material spec bodies

Where the property numbers come from.

Spec body Origin Applies to Example
AMS SAE Aerospace Material Spec Aerospace metals, fasteners, processes AMS 4928 — Ti-6Al-4V bar, annealed
ASTM American Society for Testing & Materials Cross-industry — metals, plastics, ceramics ASTM B348 — titanium bar, billet, wire
MIL-DTL / MIL-STD U.S. Military detail/standard Defense procurement MIL-DTL-5541 — chemical conversion coatings
AISI / SAE American Iron & Steel Institute / SAE Carbon and alloy steels AISI 4140 — Cr-Mo alloy steel
UNS Unified Numbering System Cross-reference for all metals UNS S31603 = AISI 316L stainless
ISO International Organization for Standardization International equivalents ISO 5832-3 — wrought Ti-6Al-4V for surgical implants
DIN / EN European standards European equivalents EN AW-6061 = ASTM 6061-T6 aluminum
FDA / USP U.S. food & pharma compliance Food contact, medical implant USP Class VI — pharma contact materials

Drawings often invoke multiple specs simultaneously. The AMS spec defines the alloy, an ASTM spec covers the form, and a MIL spec might call out testing and certification. We supply CMTRs traceable to the strictest spec invoked.

03 · Export control

ITAR vs EAR: which regulates your part?

U.S. export control divides products and technical data into two systems: ITAR covers explicitly defense articles (anything on the U.S. Munitions List). EAR covers dual-use commercial items (commerce regulated, often less strict). Knowing which applies determines how customers can share drawings with us — and who can work on the parts.

ITAR

International Traffic in Arms Regulations

22 CFR 120-130. Administered by U.S. Department of State, Directorate of Defense Trade Controls (DDTC). Covers defense articles, defense services, and related technical data on the U.S. Munitions List (USML).

  • ·Manufacturer must be registered with DDTC
  • ·Technical data sharing with foreign persons requires license
  • ·Export of defense articles requires authorization (DSP-5 license or exemption)
  • ·Penalties: $1M per violation, criminal liability

EAR

Export Administration Regulations

15 CFR 730-774. Administered by U.S. Department of Commerce, Bureau of Industry and Security (BIS). Covers commercial and dual-use items on the Commerce Control List (CCL).

  • ·Items classified by ECCN (Export Control Classification Number)
  • ·License requirements vary by destination + end-use + end-user
  • ·Most commercial items don’t require export license to allied countries
  • ·EAR99 designation = baseline non-controlled commercial

04 · Defense procurement

Clauses you'll see in DoD contracts.

DFARS

Defense Federal Acquisition Regulation Supplement

DoD's supplement to FAR. The clauses define how DoD buys things: domestic specialty metals (DFARS 252.225-7008), supply chain risk (252.239-7017), and many more.

DFARS 252.204-7012

Safeguarding Covered Defense Information

The cybersecurity clause. Requires NIST SP 800-171 compliance for protecting CUI on contractor systems. Foundational for CMMC requirements.

DPAS

Defense Priorities and Allocations System

Priority-rated DoD contracts. DX rated = top priority, DO rated = standard priority. Suppliers must accept rated orders ahead of unrated commercial.

CMMC

Cybersecurity Maturity Model Certification

DoD program that certifies contractor cybersecurity. Levels 1-3 with corresponding NIST 800-171 controls. Required for handling CUI in DoD supply chain.

Berry / Buy American

Domestic content rules

Buy American Act / DFARS 252.225 require domestic-origin specialty metals (and food, fabric, hand tools). Origin certification flows down with the PO.

Specialty Metals (DFARS)

Domestic melt requirement

DFARS 252.225-7008/9 limits the source of specialty metals (titanium, certain alloy steels, Inconel) to U.S. or qualifying countries. Verify at PO time.

05 · Drawing standards

GD&T symbols and what they mean.

ASME Y14.5 is the U.S. drawing standard for geometric dimensioning and tolerancing. ISO 1101 is the international equivalent — most concepts map but call-out style differs. The 14 GD&T symbols and their applications:

Key: Form (4) · Profile (2) · Orientation (3) · Location (3) · Runout (2) — 14 symbols grouped by what they control.

Symbol Type Name Controls
Form Straightness Linear deviation along an axis or surface line
Form Flatness Surface variation from an ideal plane
Form Circularity Round cross-section deviation
Form Cylindricity Combined roundness + straightness along axis
Profile Profile of a line Cross-sectional shape deviation
Profile Profile of a surface 3D surface deviation from ideal shape
Orientation Perpendicularity 90° relationship to a datum
// Orientation Parallelism Parallel relationship to a datum
Orientation Angularity Specified angle to a datum
Location Position Where a feature sits relative to datums
Location Concentricity Median points coincide with datum axis (Y14.5-2018: removed; ISO retains)
Location Symmetry Median plane coincides with datum (Y14.5-2018: removed; ISO retains)
Runout Circular runout Combined deviation as feature rotates
Runout Total runout Combined runout across the full feature length

ASME Y14.5

U.S. dimensioning and tolerancing standard. Latest version: Y14.5-2018. Most aerospace and defense work invokes this.

ISO 1101 / 8015

International equivalent for geometric tolerancing. Different default datum-feature interpretation than Y14.5 — verify which applies.

ASME Y14.100

Engineering drawing practices. Title block, line types, projection conventions. The general 'how to draw a drawing' standard.

06 · Glossary

Acronyms you'll see.

AMS
Aerospace Material Specification (SAE)
AS9100
Aerospace QMS standard
AS9102
First Article Inspection standard
AISI
American Iron & Steel Institute
ASTM
American Society for Testing & Materials
ASME
American Society of Mechanical Engineers
BIS
Bureau of Industry & Security (Commerce)
CAGE
Commercial and Government Entity code
CCL
Commerce Control List (EAR)
CMM
Coordinate Measuring Machine
CMMC
Cybersecurity Maturity Model Certification
CMTR
Certified Material Test Report
CNC
Computer Numerical Control
CTE
Coefficient of Thermal Expansion
CUI
Controlled Unclassified Information
DDTC
Directorate of Defense Trade Controls
DFARS
Defense FAR Supplement
DFM / DFMA
Design for Manufacturing / Assembly
DOC
Depth of Cut
DPAS
Defense Priorities & Allocations System
DUNS
D&B Universal Numbering System
EAR
Export Administration Regulations
ECCN
Export Control Classification Number
EDM
Electrical Discharge Machining
FAA
Federal Aviation Administration
FAI
First Article Inspection
FAR
Federal Acquisition Regulation
FDA
Food & Drug Administration
FOD
Foreign Object Debris
GD&T
Geometric Dimensioning & Tolerancing
HAZ
Heat Affected Zone
HRC / HRB
Rockwell Hardness, C or B scale
HSS
High-Speed Steel (tooling)
HV / HB
Vickers / Brinell hardness
IACS
International Annealed Copper Standard
IPM
Inches Per Minute (feed rate)
IPR
Inches Per Revolution
IPT
Inches Per Tooth (chip load)
ISO
International Organization for Standardization
ITAR
Intl. Traffic in Arms Regulations
JIT
Just-In-Time (inventory)
LTA
Long-Term Agreement
MES
Manufacturing Execution System
MIL-DTL
Military Detail Specification
MIL-STD
Military Standard
MRB
Material Review Board
MQL
Minimum Quantity Lubrication
MRP
Material Requirements Planning
NIST
National Institute of Standards & Technology
OD / ID
Outside / Inside Diameter
OEM / OCM
Original Equipment / Component Manufacturer
PO
Purchase Order
PVD / CVD
Physical / Chemical Vapor Deposition
Q&T
Quench and Temper
QMS
Quality Management System
Ra
Roughness average (surface finish)
RFQ
Request for Quote
RoHS
Restriction of Hazardous Substances
SAE
Society of Automotive Engineers
SCC
Stress Corrosion Cracking
SFM
Surface Feet per Minute
SOC
Statement of Conformance
SPC
Statistical Process Control
SS
Stainless Steel
STA
Solution Treated and Aged
UTS
Ultimate Tensile Strength
UNS
Unified Numbering System
USML
U.S. Munitions List (ITAR)
WEDM
Wire EDM
YS
Yield Strength

Have a part that needs to be made right?

Tell us about your part and we'll quote within 24 hours. Aerospace, medical, and defense work welcome.

Quotes in 24 hours