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Tombstones
Tombstones that provide a reliable choice for precision workholding in demanding applications.
Machine Tool Ecosystem
Workholding Foundations
Tombstones, fixture plates, trunnion tables, and more that hold the tightest tolerances in the industry.
Which Tombstone
is right for me?
is right for me?
Machine brand
Machine model
— or —
Pallet size
Table dimensions aren't available for this model.
Select a pallet size directly, or contact us for help matching your machine.
Machine brand
Machine model
— or —Pallet size
Workholding Foundations
Beyond the Industry Standard
AMROK, the workholding division at Hennig, 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 our 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
Product Lineup
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.
Martin 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.
5-Axis Pyramids
Designed for multi-sided CNC machining with optimal face angles, precision bushings, and customizable configurations.
Magyver Plate Universal Adapter
The magyver reducer/universal adapter plate easily adapts CNC tombstones with smaller footprints to machines with larger pallets.
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) | 0.0005 / 12x12 |
| Parallelism (plates) | .0005 / 12 Max .002 total |
| Perpendicularity | .0008 / 12 Min .001, Max .002/48 |
| Surface Finish | 63 RMS |
| Face Thickness | ≤18” = ±.002, >18” = ±.003 |
| Tapped Holes (non-accumulative) | ±.005 |
| Precision Bushing I.D. | +0.0013 / +0.0007 |
| Precision Bushing Concentricity | 0.0001 |
| Bored or Precision Bushing Hole to Adjacent Hole | ±0.0005 |
| 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.
Setup Time Calculator
How Much Is Setup Time Costing You?
Every changeover means idle spindle time. Multi-part fixturing slashes setup frequency — so your machines spend more hours cutting and less time waiting.
Your Machines
$
The Setup Problem
min
%
Annual Cost of Fixture Changeovers
1,500 hrs
Spindle Hours Lost to Setup / Year
$263K
Annual Lost Production Value
$131K
Recoverable with Workholding
Based on 250 working days/yr. Multi-part fixturing reduces changeover frequency so your spindle spends more time cutting.
Still Looking for Answers?
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.
- 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.
- 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.
Standard Products: You’ll receive the quote within 1-2 business days.
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.
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.
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 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 which can be found here.
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.
- Custom Hydraulic Fixtures start with AMRH-XXXX or BOR-XXXX
- Custom Manual Fixtures start with AMRM-XXXX or BOR-XXXXX
- Custom Pneumatic Fixtures start with AMRP-XXXX or BOR-XXXX
From the Resource Hub
Related Content
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Finding the Right Tombstone is Easy with Hennig
Read our handy guide on how to select the right tombstone from their wide range of products.
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Ready to Rock! - Epoxy Mineral Tombstones
Dr. Tony Schmitz, a professor specializing in vibration analysis, came to AME to do a series of tests on the various material types of tombstones and breaks down his findings to determine the best type of tombstone for your shop.
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Why You Should Consider Off-Machine Setups for Your Machining Process
If you want to reduce your overall costs and increase your flexibility to meet your customers’ demands, consider incorporating off-machine set-ups into your machining process.