F4 Industries YC Application

Summer 2025Active

F4 Industries went through Y Combinator in the Summer 2025 batch as a Industrials company. Below: what the company does, who founded it, and its application to YC, reconstructed question by question in the real YC form.

YC batch: Summer 2025
Industry: Industrials
Team size: 5
Status: Active
Launched: 2025

Founders

Paul ShinFounder
Aidan CantuCTO & Co-Founder

What F4 Industries does

GD&T takes years to master. Engineers must encode their design intent into a dense syntax that manufacturers must decode, and not everyone gets it right. Put ten engineers in front of the same drawing and you may get ten different interpretations. Which means errors often surface later in interface stack-ups, manufacturing, or in the field - when they’re far more expensive to fix. That’s why we built F4 - the platform that analyzes GD&T to determine whether your designs are ready for production. Drop in your drawing and 3D file. F4 analyzes every element of your GD&T to assess whether your design is clear, manufacturable, and production ready. To make the drawing easier to understand, engineers can visualize their datums, reference frames, and tolerance zones directly on the 3D model. F4 also calculates tolerance stack-ups instantly - directly from the drawing. What once took hours of manual work now takes seconds. When issues are found, F4 flags them and guides engineers toward resolving the problem. After analyzing your drawing, F4 also automatically generates design and inspection reports - stack-up tables, FAI reports - ready to share with your team. And it does all of this locally on-device with no AI used for analysis. Producing deterministic results engineers can trust.

F4 Industries's YC application, reconstructed

Y Combinator application

F4 Industries, Summer 2025 batch. The real form questions, answered from public data.

Founders2
Company7
Progress7
Idea4
Equity3
Curious2
Batch Preference1

Company

Company name

F4 Industries

Describe what your company does in 50 characters or less.

The GD&T Analysis Platform for Engineering Drawings

What is your company going to make? Please describe your product and what it does or will do.

We built F4 to analyze engineering drawings with GD&T annotations and 3D files, making it clear if designs are ready for manufacturing. Drop in a drawing and model; F4 checks every GD&T element, visualizes reference frames on 3D, calculates tolerance stack-ups instantly, and flags issues engineers can fix before production.

Where do you live now, and where would the company be based after YC?

We live in San Francisco, CA, and the company will be based here after YC as well.

Explain your decision regarding location.

San Francisco puts us close to industrial customers and manufacturing hubs intersecting with tech, plus the YC community itself is here.

21 more answers in the full application

Founders, Progress, Idea, Equity, Curious, Batch Preference are in the full version. Create a free account to open it in YC Insights, next to every other YC batch.

See full application

Frequently Asked Questions

Is this the real F4 Industries YC application?

No. Y Combinator keeps submitted applications private. This is a reconstruction: the real YC form questions, answered from F4 Industries's public data (launch notes, founder backgrounds, product description). It shows how a company like F4 Industries would present itself to YC, not the text they submitted.