Legend with slds-box Lightning Salesforce

	<aura:component implements="force:appHostable,flexipage:availableForAllPageTypes,flexipage:availableForRecordHome,force:hasRecordId,forceCommunity:availableForAllPageTypes,force:lightningQuickAction" access="global" >
	<!--
	1. Use fieldset for the compound form
	-->
	<div class="slds-grid slds-glutters">
	<div class="slds-col"></div>
	<div class="slds-col">
	<fieldset class="slds-box"> <!-- This is for box border -->
	<legend class="slds-text-heading--small">My Heading</legend> <!-- This is for heading -->
	<div class="slds-form-element__control">
	my content
	</div>
	</fieldset>
	</div>
	<div class="slds-col"></div>
	</div>
	</aura:component>

view raw LegendWithBoxLightning hosted with ❤ by GitHub

Screenshot -