Building a Custom WordPress Theme for a CNC Manufacturer

When a precision manufacturing company with 50 years of history asks you to build their web presence from the ground up, you take that brief seriously. That’s exactly what we did for Delta Machine & Tool Co., Inc. – an AS9100 Rev D certified Tier-1 CNC precision machining manufacturer based in West Chester, PA, serving aerospace, defense, medical device, and industrial OEM customers since 1975.

This post is a full breakdown of the project – what we built, why we made the decisions we did, and what other manufacturing companies can take away from it.

About the Client

Delta Machine & Tool Co. is not a typical small business website project. They are a Tier-1 OEM supplier producing tight-tolerance precision machined components and assemblies for some of the most demanding programs in aerospace and defense. Their capabilities include CNC milling, CNC turning and turn-mill, simultaneous 5-axis machining, Swiss screw machining, EDM and wire EDM, and precision grinding – all operating under their AS9100 Rev D quality management system.

They hold tolerances to ±0.0002″ and maintain a 99.8% on-time delivery record. Their customer base includes some of the largest aerospace and defense OEMs in the country, and they’ve received a Performance Excellence Award from a leading defense contractor. In short: the website needed to communicate world-class credibility to procurement engineers and supply chain managers – not general consumers.

The Brief

The project started with a clear goal: replace an outdated site with a custom-built WordPress theme that would:

Perform at or near 100 on Google Lighthouse across all four categories
Pass WCAG 2.1 AA accessibility compliance (we targeted A+ on automated scans)
Rank for precision machining and CNC machining keywords in their regional market
Generate qualified leads through a multi-step quote request form with file upload
Be fully maintainable by a non-technical client without a page builder or monthly plugin subscriptions

No page builders. No Elementor. No licensing fees. Just a clean, hand-coded WordPress theme built to last.

Tech Stack

We built everything from scratch using a stack we’ve refined across manufacturing and industrial B2B projects:

WordPress – custom theme, no page builder
Bootstrap 5.3 – grid and utility base, heavily overridden with custom design tokens
Sora (display) and DM Sans (body) via Google Fonts
Advanced Custom Fields (ACF) – for per-page JSON-LD schema injection and a custom Location CPT for geo-targeted landing pages
Yoast SEO – for WebPage, BreadcrumbList, and Article schema, plus per-page meta
Custom AJAX quote form – built in-house using wp_mail() and WordPress nonces, no plugin dependency
WP Mail SMTP – for reliable mail delivery via cPanel SMTP

This is the kind of stack we reach for when the client needs long-term maintainability without recurring plugin costs. You can read more about how we approach manufacturing web projects on our services page.

Design System

The entire site is built on a single CSS custom property design system – no Sass, no build step, no compilation. Every color, spacing unit, transition, and shadow is defined as a CSS variable, making global changes a one-line edit.

The palette is built around a deep navy and cobalt primary with gold accents – intentional choices that communicate industrial precision and authority without feeling generic. The typography pairing of Sora (geometric, technical, high-contrast) with DM Sans (highly legible body text at small sizes) was chosen specifically for a B2B audience reading on desktop in procurement or engineering contexts.

Every interior page uses a consistent blueprint-grid hero pattern – an immersive full-width banner with scan lines, tick marks, and a cobalt accent bar that establishes the industrial aesthetic before the user reads a single word.

Lighthouse Performance – Targeting 100

Getting to 100 on Google Lighthouse on a WordPress site requires deliberate decisions at every layer of the stack. Here’s what we did:

Deferred all JavaScript – Bootstrap and our custom scripts.js both load with the defer attribute, eliminating render-blocking resources entirely
Stripped WordPress bloat – removed emoji scripts (~10 KB), Gutenberg block CSS (~70 KB), wlwmanifest, RSD link, and XML-RPC
Resource hints – preconnect to Google Fonts and jsDelivr CDN in the <head> before wp_head()
Native lazy loading – wp_lazy_loading_enabled filter returns true globally; hero images use fetchpriority="high" and loading="eager"
Cache-busting via filemtime() – stylesheet and script versions are derived from file modification time so browsers always serve fresh assets after deploys
WebP and AVIF support – added to WordPress MIME type whitelist so clients can upload next-gen image formats
Custom image sizes – four registered sizes (hero, card, band, thumb) ensure WordPress generates appropriately sized srcset variants for every context

WCAG 2.1 AA Accessibility

Accessibility compliance on B2B manufacturing sites is often an afterthought. We treat it as a first-class requirement – both because it’s the right thing to do and because WCAG compliance increasingly affects search rankings and legal exposure.

On this project we implemented:

Skip link – visually hidden until focused, targeting #main with tabindex="-1" for programmatic focus support in Safari
Landmark roles – semantic <header>, <nav>, <main>, <footer>, every <section> labelled with aria-labelledby
Custom nav walker – Bootstrap 5 dropdown walker outputs aria-current="page", aria-expanded, and aria-haspopup on the correct elements
All decorative SVGs are aria-hidden="true"; meaningful SVGs carry role="img" and a title
Heading hierarchy – enforced site-wide: H1 per page, section intros H2, card titles H3, sub-items H4 – never skipping levels
Color contrast – all text passes AA contrast ratios; interactive elements exceed 3:1 non-text contrast
Keyboard navigation – all interactive elements reachable and operable by keyboard; dropdown nav uses hover on desktop and tap-to-expand on mobile without trapping focus

We follow the WCAG 2.1 guidelines on every project. You can learn more about how we approach accessibility in our accessibility compliance guide.

SEO Architecture

Manufacturing SEO is a specialist discipline. The buyers are engineers and procurement managers using highly specific search queries – not general consumers. The strategy we built for Delta targets three layers:

Technical SEO

Yoast SEO handles WebPage, BreadcrumbList, and Article schema per page
A custom global LocalBusiness JSON-LD block outputs geo coordinates, opening hours, AS9100 credential data, and the Performance Excellence Award – none of which Yoast outputs by default
Per-page Service and FAQPage schema is injected via an ACF WYSIWYG field (schema_data) – editors paste raw JSON-LD, it’s validated server-side before output
Canonical URLs, hreflang-ready structure, and XML sitemap via Yoast

On-page SEO

Every capability page targets a specific long-tail keyword: “CNC milling services aerospace,” “multi-axis machining West Chester PA,” etc.
Rich semantic HTML – spec tags, cert pills, process step markup – give search engines dense, structured content signals
Internal linking between capabilities, services, markets, and quality pages builds topical authority

Local SEO

A custom Location CPT powers geo-targeted county landing pages at /locations/{county}/ – each with unique local intro content, cities served, local industry context, and a local FAQ
Pages are designed to stay clear of Google’s doorway page penalty by requiring genuinely unique local content per county
LocalBusiness schema with areaServed on each location page provides structured local signals

The Quote Request Form

This was one of the most technically involved pieces of the project. Aerospace and defense procurement engineers need to upload engineering drawings – PDFs, DWG files, STEP files, IGES files – when requesting a quote. Off-the-shelf free form plugins don’t support file uploads.

We built a custom multi-step AJAX form entirely from scratch:

4-step wizard UI – contact info, part details, file upload, review and submit
Drag-and-drop file upload with client-side type and size validation (PDF, DWG, DXF, STEP, IGES, JPG, PNG, TIFF – up to 50 MB per file, 10 files max)
Server-side re-validation in PHP – never trusting client JS alone; extension whitelist, size check, is_uploaded_file() verification
Secure temp file handling – uploaded files are moved to a private quote-temp/ directory protected by .htaccess, attached to wp_mail(), then immediately deleted after send
WordPress nonce verification on every submission – prevents CSRF attacks
Honeypot spam protection – catches the vast majority of bots without reCAPTCHA friction
Dual email send – internal notification to the Delta team with Reply-To set to the submitter, plus a confirmation email to the submitter with a submission summary

The entire handler lives in inc/quote-form.php and is loaded via a single require_once in functions.php – self-contained, no plugin dependencies, no recurring license costs.

What We Learned

A few things worth noting for anyone building in this space:

B2B manufacturing buyers read everything. This audience is technical. They read spec tables, tolerance callouts, and quality documentation sections. Dense, accurate content outperforms sparse “hero + CTA” layouts that work for consumer sites.

File uploads are a first-class feature, not an add-on. For any industrial or professional services site where the lead generation action involves submitting a document – a drawing, an RFQ, a spec sheet – you need a robust upload path. Build it properly or lose leads to a broken UX.

Schema matters more in B2B than most people realise. Procurement teams often find suppliers through very specific SERP features – LocalBusiness rich results, FAQPage accordions, breadcrumbs. Taking the time to output rich, accurate structured data pays dividends in a niche with lower competition than consumer markets.

Accessibility compliance is non-negotiable. Defense and aerospace primes increasingly require their supplier websites to meet WCAG standards as part of supplier qualification. It’s not just good practice – in this sector it’s becoming a commercial requirement.

See the Work

The live site is at deltamachineandtool.com. You can explore their full capabilities, quality program, and their quote request form to see all of the above in action.

You can see this and other projects in our portfolio.

If you’re a manufacturer, industrial supplier, or B2B professional services company looking for a custom WordPress build with this level of attention to performance, accessibility, and SEO – let’s talk. We build sites that work as hard as the businesses they represent.

Built with WordPress, Bootstrap 5, Advanced Custom Fields, and Yoast SEO. Designed and developed by Mediamato.