Mold Texture Spec Kit

The texture problem nobody sees until the steel is cut

Texture is the last operation on the tool and the first thing the customer touches. By the time anyone sees a molded part, the cavity has been machined, polished, etched and shipped. If the specification was vague, the mistake is now in hardened steel.

It rarely fails in a dramatic way. It fails in small, expensive ones:

• The drawing says "VDI 30" and nothing else. The shop applies it to the core side, the ribs and the shut-off faces. Nobody wrote where the texture stops.
• The part was designed with 1° of draft for a polished finish. Marketing then asked for a leather grain. Nobody went back to the draft. The first shots drag on ejection and leave bright scuff lines on the walls.
• The texture plaque was approved in ABS, black, under office light. Production runs in PC/ABS, gray, and the customer audits under a different source. The gloss does not match and the plaque proves nothing.
• Your toolmaker overseas quotes a Yick Sang code. Your drawing calls out Mold-Tech. Someone emails a "conversion chart" that treats two different measurement systems as if they were the same scale.
• The texture shop says the job meets spec. Your quality team says it does not. There is no written acceptance criterion, so the argument is about opinion, and the schedule slips while everyone argues.

Each of these is a specification problem, not a craftsmanship problem. Each one costs rework, re-etching or a delayed launch, and any one of them costs more than this kit many times over. And each one could have been prevented on paper, before a single tool left the machine shop.

Why texture charts alone do not solve it

There is no shortage of texture charts. Molders and suppliers hand out sample plaques and PDF charts at no cost, and they are useful for one job: showing what a finish looks like.

A chart does not answer the questions that decide whether the part ships on time:

The Spec Kit is built for the right-hand column.

What is inside the Mold Texture Spec Kit

Five working modules. Each one is a file you open and use on a live project, not a chapter you read once.

An example of what "ready to use" means

This is the format of a Module 1 callout. The kit carries one for each texture system and variants for partial texture, grain direction and multi-cavity tools.

Illustrative example. Not a measured sample. Adapt surfaces, references and approval steps to your drawing standard.

Notice what it does: it says where the texture goes, where it does not, who confirms the draft, what the acceptance master is, how gloss is recorded, and when the work happens. That is the difference between naming a finish and specifying one.

Look inside: Edition 1.0 contents

The manual is organized by the decision you are making, not by standard. Each part ends with the file that applies it.

Inside the cross-reference, every row carries its basis: the published standard it relates to, or a marked approximation with its limit. You always know which values you can put in a contract and which ones are guidance.

Sample rows from the Cross-Reference Library

Ra values calculated from the VDI 3400 grade relationship and rounded. 1 µm = 39.37 µin. The full library covers every VDI grade from 0 to 45 with its Charmilles designation and default cutoff, adds SPI grades with two published Ra references and approximate VDI ranges, and explains how library patterns such as Mold-Tech and Yick Sang compare, each with its basis and limit.

That last column is the point. A chart that prints "VDI 30 = MT-11010" gives you a number to argue about later. The kit tells you which relationships are defined, which are approximate, and which do not exist, so the contract only carries values that hold up.

The kit at a glance

Where each module fits in your program

Texture decisions are spread across months of a tool build, and most of them are made by different people. The kit follows the same sequence, so the right file is open at the right gate.

Most texture disputes trace back to a decision that was skipped at one of these gates. The kit makes each gate a short, documented step instead of an assumption.

Who it is for

• Product and design engineers who release drawings with textured surfaces and need the callout to be unambiguous the first time.
• Tooling engineers and buyers who send tools to domestic or offshore shops and need specifications and RFQs that survive translation between texture systems.
• Mold makers who receive vague texture requests and want a standard way to confirm scope, draft and approval before etching.
• Texturing and engraving shops that want a clear acceptance document their customers will sign before the work starts.
• Molders and quality engineers who end up judging texture on production parts and need a written criterion instead of an argument.
• Automotive supplier quality teams who must document texture and gloss in the PPAP Appearance Approval Report and defend it at the customer audit.

Who it is not for

If you need a general introduction to what mold texture is, the free reference pages on this site cover it, and you do not need the kit. The kit is for people who have to put a texture on a drawing, a purchase order or an approval form, and be accountable for it.

Why this kit can be trusted

The kit is written and reviewed by the Mold Texturing Guide technical editorial team, the same team behind the site's reference pages on VDI 3400, SPI finishes, Mold-Tech textures and cross-standard conversion, visited by engineers from more than 50 countries in the last three months, according to Google Search Console. The decision rules in the kit, such as when an approximate conversion is acceptable, how much to adjust draft for deeper textures and what to check before approving a plaque, come from shop-floor texturing practice, not from desk research.

The kit follows three rules that we apply on every page of this site:

• No invented numbers. Values taken from published standards cite the standard by number. Example values are marked as examples.
• No false equivalence. SPI, VDI 3400, Mold-Tech and Yick Sang describe finishes in different ways. Where the kit relates them, it states the limits of the comparison.
• No customer data. Examples are illustrative and representative of typical shop conditions. No customer, part or program is identified.

What the kit is not

• It is not a copy of any standard. It references VDI 3400, SPI, ISO and ASME documents by number and helps you apply them. If your contract requires a standard, buy the standard.
• It is not a texture catalog. Mold-Tech, Yick Sang and other pattern libraries belong to their owners and are named only to identify them.
• It is not a service. Nobody will texture, polish or repair a tool for you through this page.
• It does not replace engineering approval on your program. It makes that approval faster and better documented.

Frequently asked questions

Mold Texturing Guide is an independent technical publication. VDI 3400, SPI, ISO and ASME documents are the property of their respective publishers. Mold-Tech, Yick Sang, Tanazawa, Eschmann and Charmilles are trademarks of their respective owners and are named only for identification. PPAP and the Appearance Approval Report are AIAG publications; the kit's texture approval record is an independent document designed to support them, not a copy of the AIAG form. All examples in this kit are illustrative. The kit does not replace official standards or the engineering approval required on your program.