What Is an MTO?

Quick Answer

A Material Take-Off (MTO) is a detailed list of every piping component—pipes, fittings, flanges, valves, gaskets, and bolts—required for a project, extracted from engineering drawings. The MTO translates design documents into procurement quantities. It is the foundation for RFQs, purchase orders, and project cost estimates.

What an MTO Includes

An MTO itemizes each component with its full technical description, specification, quantity, and unit of measure. A single piping line may generate dozens of MTO line items.

MTO Field	Description	Example
Item number	Sequential reference	001, 002, 003
Description	Full technical description	6” LR 90-deg elbow, BW, Sch 40
Material spec	ASTM/API grade	ASTM A234 WPB
Size	NPS or DN	6” (DN 150)
Schedule/class	Wall thickness or pressure rating	Sch 40 / Class 150
Quantity	Count or length	12 EA / 450 meters
Unit	Pieces, meters, kg	EA, LM, KG
Pipe class	Project pipe class code	A1A
Drawing reference	Source P&ID or isometric	ISO-PIP-1001-001

Sources for MTO Data

MTOs are generated at different project stages using different source documents:

Project Phase	Source Document	MTO Accuracy
FEED / early engineering	P&IDs, equipment layouts	+/- 25-30% (bulk estimate)
Detailed engineering	Piping isometrics, GA drawings	+/- 5-10% (line-by-line)
Construction / as-built	Field-verified isometrics	Final quantities

Early-phase MTOs are called “bulk MTOs” and are used for budgeting and long-lead item procurement. Detailed MTOs extracted from piping isometrics are the basis for final purchase orders.

How MTOs Are Generated

Modern EPC projects generate MTOs from 3D piping design software (AVEVA E3D, Intergraph Smart 3D, Hexagon PDS). The software extracts component lists directly from the model, reducing manual error. For smaller projects or brownfield work, MTOs may be compiled manually from isometric drawings.

The typical workflow:

1. Piping designer completes isometric drawings per P&ID and pipe class requirements
2. Software extracts component data from the 3D model
3. Materials engineer reviews and validates against the pipe class
4. Procurement engineer consolidates MTOs by material type for bulk purchasing
5. RFQs are issued to pre-qualified vendors

Pro Tip

Always add a contingency factor to MTO quantities: 5-10% for pipes (cutting waste, field adjustments) and 3-5% for fittings and flanges (damage, rework). Under-ordering causes construction delays; over-ordering creates surplus inventory. Most EPC contractors have standard contingency tables by component type.

MTO vs BOM vs BOQ

These terms are sometimes used interchangeably but have distinct meanings:

Document	Full Name	Scope
MTO	Material Take-Off	Quantities extracted from engineering drawings
BOM	Bill of Materials	Complete parts list for a system or assembly
BOQ	Bill of Quantities	Priced quantities for tendering (includes labor, materials)

The MTO feeds into the BOM, which feeds into the BOQ. For piping procurement, the MTO is the primary working document.

Accurate MTOs drive accurate procurement and prevent costly field shortages. A 5% error on a large-diameter alloy pipe order can mean weeks of delay and tens of thousands of dollars in expediting costs.

Read the full guide to pipe classes and specifications