AMROK WORKHOLDING FOUNDATIONS

Tombstones, fixture plates, trunnion tables, and more that hold the tightest tolerances in the industry.

beyond the industry standard

AMROK, the workholding division at AME, has built a steady reputation for incomparable flatness, parallelism, perpendicularity, surface finish, and hole location across its line of workholding foundations. Every foundation undergoes a rigorous inspection process using AME's in-house coordinate measuring machine (CMM). 

If you require repeatable, precise, and trustworthy workholding foundations, it’s time to talk with our experts about what AMROK can provide, in-house and in the U.S.

workholding foundations

AMROK Cast Iron Tombstones
AMROK Cast Iron Tombstones
Tombstones that provide a reliable choice for precision workholding in demanding applications.
Epoxy Mineral Tombstones
Epoxy Mineral Tombstones
Swiss Modular's tripoxyMINERAL tombstones provide a lightweight, vibration-damping alternative to cast iron, delivering stable machining performance with minimized thermal expansion and chemical resistance.
Fixture Plates & Grid Plates
Fixture Plates & Grid Plates
Precision AMROK fixture plates and grid plates are customized for your machine tool and checked with CMM to ensure quality. Made in a variety of shapes, sizes, materials.
4th Axis Trunnion Tables & Rotary Tables
4th Axis Trunnion Tables & Rotary Tables
4th axis CNC workholding fixtures are designed to greatly increase efficiency of VMCs. AMROK offers complete 4th axis solutions for your machine tool.

Machining and Tolerancing for Tombstones

  • Inserts allow positioning and clamping in every hole with co-axial positioned bushings.
  • Hardened precision bushings are easily replaceable and assure high wear resistance.
  • Replacement bushings and insert kits with an extraction tool are offered if needed.
Tolerance Precision
Flatness (tombstones & plates).0005 / 12x12
Parallelism (plates).0005 / 12 Max .002 total
Perpendicularity.0008 / 12 Min .001, Max .002/48
Surface Finish63 RMS
Face Thickness≤18” = ±.002, >18” = ±.003
Tapped Holes (non accumulative)±.005
Precision Bushing I.D.+0.0013 / +0.0007
Precision Bushing Concentricity0.0001
Bored or Precision Bushing Hole to Adjacent Hole±.0005
First Row Bushing Hole Location from Datums±.002
Bored or Precision Bushing Hole Spacing (non accumulative) 0-10 ±.0005, 10-20 ±.0008, 20-30 ±.0010, 30-40 ±.0012
(for aluminum, add 50% to these tolerances)

RESOURCE HUB

Empower yourself with the resources to make an informed decision and get up and running quickly.

Our team is here to help at every step. If you have questions or need guidance on selecting the right fixture, contact our workholding experts for personalized assistance. We’re happy to provide recommendations or even a custom fixture design review to ensure you get the most out of your investment.

Manufacture Success Blog

Workholding Featured Posts

Finding the Right Tombstone is Easy with AME
Finding the Right Tombstone is Easy with AME

AME provides a handy guide on how to select the right tombstone from their wide range of products.

Read Our Blog >>

The Most Important Tool for Your CNC Machine Isn’t a Cutting Tool
The Most Important Tool for Your CNC Machine Isn’t…

The Power-Check 2 Drawbar Pull Force Gage from OTT-JAKOB helps keep your machine spindle drawbar force in tolerance. Here’s why that’s so important.

Read Our Blog >>

Overview of Workholding System Components - Part 2
Overview of Workholding System Components - Part 2

The one component that is common to all workholding systems is a method for clamping the part(s). As we discussed earlier, machining involves forces that can be significantly high, and a clamping system is needed to restrain...

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FREQUENTLY ASKED QUESTIONS

The easiest way to get a quote is by using the "Request Quote" button found on the site. If possible, give a clear definition of the part number and quantity requested. Email and phone requests are also accepted.

  1. AMROK Foundations (tombstones, grid plates and trunnion tables): In addition to the part number you’re interested in, tell us your machine make and model.
  2. Custom Fixture Design and Build: Use the "Request Quote" button, and we’ll contact you directly. We’ll likely need prints and models of your parts at some point and will be happy to sign an NDA if needed.

  1. Standard Products: You’ll receive the quote within 1-2 business days.
  2. Custom Design and Build Workholding: These quotes can vary, depending upon design inputs and engineering requirements/workload. Our team will follow up and give you an estimate on how long your quote will take.

We can do both! More than 95% of tombstones are cast iron, but we do cast aluminum, epoxy mineral, and aluminum and steel weldment, depending on the application and its requirements.

  1. Tombstones: We keep stock of commonly ordered castings in specific sizes. We take these castings from stock and machine to your specification within 2-3 weeks. Our team generally does not stock finished tombstones.
  2. Design and Build Fixtures (manual, pneumatic or hydraulic): Projects for design and build can take 6-8 weeks or longer depending on the specification and the duration of the design and approval process.

Each tombstone and/or design and build fixture is inspected on our CMM’s to verify compliance to specification. Design and build fixtures have an additional approval and validation phase with the customer.

We use SOLIDWORKS 2018 for our designs, SOLIDWORKS CAM for cutting and programming, and Vericut for cutting path verification.

We can use a variety of brands depending on the specific application or customer preference. In addition to integrating our own products, our team utilizes fixturing options from our Build on the Rock (BOTR) partners: 5th Axis, Martin Trunnion, Mitee-Bite, Schunk, Triag, and Vektek.

Yes! We have developed many hydraulic and pneumatic fixtures.

There are many different variables that are considered when choosing a tombstone material. Review our whitepaper on Tombstone Testing for Dynamic Performance compiled by Tony Schmitz, PhD. to learn more about how to choose the best material for your application, including analysis on vibration, damping, and more. Download it here.

  1. Custom Hydraulic Fixtures start with AMRH-XXXX or BOR-XXXX
  2. Custom Manual Fixtures start with AMRM-XXXX or BOR-XXXXX
  3. Custom Pneumatic Fixtures start with AMRP-XXXX or BOR-XXXX