---
type: "gdt-symbol"
name: "Projected Tolerance Zone"
symbol: "Ⓟ"
unicode: "U+24C5"
unicode_name: "CIRCLED LATIN CAPITAL LETTER P"
category: "modifier"
category_name: "Modifiers and material conditions"
datum_required: "never"
tolerance_zone: "Zone projected above the feature"
aliases: ["projected tolerance zone gdt", "projected tolerance"]
standard: "ASME Y14.5 (cited, not reproduced); ISO 1101"
verified: "August 1, 2026"
url: https://shopmath.org/gdt/projected-tolerance-zone
---

# Projected Tolerance Zone (Ⓟ) — GD&T Modifier Symbol and Meaning

Moves the tolerance zone out of the part and into the space a mating stud or dowel will occupy, for a stated projection height. It is the correct control for threaded and press-fit holes, where a small angular error inside the hole becomes a large positional error at the far end of the protruding fastener.

- **Symbol**: Ⓟ (Unicode U+24C5)
- **Category**: Modifiers and material conditions
- **Tolerance zone**: Zone projected above the feature
- **Datum reference**: never references a datum
- **Standard**: ASME Y14.5 (cited, not reproduced); ISO 1101

## Projected Tolerance Zone at a Glance

| Property | Value |
| --- | --- |
| Characteristic | Projected Tolerance Zone |
| Symbol | Ⓟ |
| Unicode codepoint | U+24C5 |
| Unicode name | CIRCLED LATIN CAPITAL LETTER P |
| Category | Modifiers and material conditions |
| Tolerance zone | Zone projected above the feature |
| Datum reference | never references a datum |
| Standard | ASME Y14.5 (cited, not reproduced); ISO 1101 |

## How Projected Tolerance Zone Behaves

Projected Tolerance Zone belongs to the modifiers and material conditions group. Change how a geometric tolerance is interpreted or verified.

## Other Modifiers and material conditions Controls

The controls in the same category — the ones a drawing is choosing between when it specifies projected tolerance zone.

| Control | Symbol | Tolerance zone or effect | Datum |
| --- | --- | --- | --- |
| [Maximum Material Condition (MMC)](https://shopmath.org/gdt/maximum-material-condition.md) | Ⓜ | States that the stated tolerance applies when the feature contains the most material — the largest pin or the smallest hole. | never references a datum |
| [Least Material Condition (LMC)](https://shopmath.org/gdt/least-material-condition.md) | Ⓛ | The mirror of MMC: the stated tolerance applies when the feature contains the least material — the smallest pin or the largest hole. | never references a datum |
| [Regardless of Feature Size (RFS)](https://shopmath.org/gdt/regardless-of-feature-size.md) | Ⓢ | The default condition since 1994: the geometric tolerance applies at whatever size the feature is actually produced, with no bonus. | never references a datum |
| [Free State](https://shopmath.org/gdt/free-state.md) | Ⓕ | Says the requirement is to be verified with no restraining force applied. | never references a datum |
| [Tangent Plane](https://shopmath.org/gdt/tangent-plane.md) | Ⓣ | Evaluates an orientation control against a plane resting on the high points of the surface rather than against every point of it. | never references a datum |
| [Unequally Disposed Profile](https://shopmath.org/gdt/unequally-disposed-profile.md) | Ⓤ | Profile band split unevenly about the true profile | never references a datum |
| [Diameter](https://shopmath.org/gdt/diameter.md) | ⌀ | Inside a feature control frame this makes the tolerance zone cylindrical rather than a pair of parallel planes. | never references a datum |

## Sources and Method for Projected Tolerance Zone

### Projected Tolerance Zone definition

- **Source**: Symbols and codepoints: Unicode Character Database (Unicode License v3). Characteristic list cross-checked against NASA MSFC GD&T Basics (public domain). Descriptions written from scratch; no ASME Y14.5 text reproduced.
- **Method**: compiled
- **Verified against**: Unicode Character Database codepoint check; 98/98 structural checks passed

### Assumptions

- Descriptions are original prose. No ASME Y14.5 definitional text, worked example or figure is reproduced — the standard is cited, not copied.
- Symbol glyphs and codepoints are from the Unicode Character Database; a drawing may render the same characteristic with a different font.
- Dataset scope: EXCLUDED: all ASME Y14.5 definitional text, worked examples and figures. Every description on this site is original prose.

**Data last verified**: August 1, 2026

## Common Questions About Projected Tolerance Zone in GD&T

### What does Projected Tolerance Zone mean in GD&T?

Moves the tolerance zone out of the part and into the space a mating stud or dowel will occupy, for a stated projection height. It is the correct control for threaded and press-fit holes, where a small angular error inside the hole becomes a large positional error at the far end of the protruding fastener.

### What is the GD&T symbol for projected tolerance zone?

Projected Tolerance Zone uses the Ⓟ symbol — Unicode U+24C5 (CIRCLED LATIN CAPITAL LETTER P). It sits in the first compartment of the feature control frame.

### Does Projected Tolerance Zone need a datum?

Projected Tolerance Zone never references a datum. It qualifies how another control is interpreted rather than establishing a tolerance zone of its own.

### What is the tolerance zone for Projected Tolerance Zone in GD&T?

The projected tolerance zone tolerance zone is: Zone projected above the feature.

## Related pages

- Previous control: [Regardless of Feature Size (RFS)](https://shopmath.org/gdt/regardless-of-feature-size.md) (Ⓢ)
- Next control: [Free State](https://shopmath.org/gdt/free-state.md) (Ⓕ)
- All symbols: [GD&T symbol reference](https://shopmath.org/gdt.md)
- Tolerances: [ISO 286 fit reference](https://shopmath.org/fits.md)

---

*Source: [ShopMath](https://shopmath.org/gdt/projected-tolerance-zone) — data verified August 1, 2026. Reference data; verify against the governing standard before manufacture.*